Calcular el módulo del vector resultante de dos vectores fuerza de 9 [N] y 12 [N] concurrentes en un punto o, cuyas direcciones forman un ángulo de a) 30˚ b) 45˚ y c) 90˚

Answers

Answer 1

Answer:

a) 20.29N

b) 19.43N

c) 15N

Explanation:

To find the magnitude of the resultant vectors you first calculate the components of the vector for the angle in between them, next, you sum the x and y component, and finally, you calculate the magnitude.

In all these calculations you can asume that one of the vectors coincides with the x-axis.

a)

[tex]F_R=(9cos(30\°)+12)\hat{i}+(9sin(30\°))\hat{j}\\\\F_R=(19.79N)\hat{i}+(4.5N)\hat{j}\\\\|F_R|=\sqrt{(19.79N)^2+(4.5N)^2}=20.29N[/tex]

b)

[tex]F_R=(9cos(45\°)+12)\hat{i}+(9sin(45\°))\hat{j}\\\\F_R=(18.36N)\hat{i}+(6.36N)\hat{j}\\\\|F_R|=\sqrt{(18.36N)^2+(6.36N)^2}=19.43N[/tex]

c)

[tex]F_R=(9cos(90\°)+12)\hat{i}+(9sin(90\°))\hat{j}\\\\F_R=(12N)\hat{i}+(9N)\hat{j}\\\\|F_R|=\sqrt{(12N)^2+(9N)^2}=15N[/tex]


Related Questions

Which best describes what is made of matter?
all living things and objects
all atoms
all solid objects and atoms
all living things

Answers

A. All living things and objects

Answer:

A: All living things and objects. I Hope This Helped!

Explanation:

Describes Matter.

What is potential energy

Answers

Answer:

Potential Energy is when the energy is kept in place the object isnt moving so it isnt creating Kinetic energy.

Answer:

[tex]\boxed{\mathrm{view \ explanation}}[/tex]

Explanation:

Potential energy is the energy stored in a body due to the body’s positioning or state.

(a) At an air show a jet flies directly toward the stands at a speed of 1220 km/h, emitting a frequency of 3270 Hz, on a day when the speed of sound is 342 m/s. What frequency (in Hz) is received by the observers?

Answers

Answer:

f' = 358442.3 Hz

Explanation:

This is a problem about the Doppler's effect. To find the perceived frequency of the observers you use the following formula:

[tex]f'=f(\frac{v}{v\pm v_s})[/tex]

v: speed of sound = 342 m/s

vs : speed of the source (jet) = 1220 km/h (1h/3600s)*(1000 m/ 1km) = 338.88 m/s  (it is convenient to convert the units of vs to m/s)

f: frequency emitted by the source = 3270 Hz

f': perceived frequency

Due to the jet is getting closer to the observers, the sing of the denominator in equation (1) is minus (-). Then, you replace the values of f, vs and v:

[tex]f'=(3270s^{-1})(\frac{342m/s}{342m/s-338.88m/s})=358442.3 Hz[/tex]

Hence, the perceived frequency by the observers is 358442.3 Hz

Answer:

[tex]f_o=359466.42Hz[/tex]

Explanation:

You can solve this problem using doppler effect formula. The Doppler effect is the phenomenon by which the frequency of the waves perceived by an observer varies when the emitting focus or the observer itself moves relative to each other

Doppler effect general case is given by:

[tex]f_o=f\frac{v\pm v_o}{v \mp v_s} \\\\Where:\\\\f=Actual\hspace{3}frequency\\f_o=Observed\hspace{3}frequency\\v=Speed\hspace{3}of\hspace{3}the\hspace{3}sound\hspace{3}waves\\v_o=Velocity\hspace{3}of\hspace{3}the\hspace{3}observer\\v_s=Velocity\hspace{3}of\hspace{3}the\hspace{3}source[/tex]

Now, you can use the following facts:

[tex]+v_o[/tex] Is used when the observer moves towards the source

[tex]-v_o[/tex] Is used when the observer moves away from the source

[tex]-v_s[/tex] Is used when the source moves towards the observer

[tex]+v_s[/tex] Is used when the source moves away from the observer

Since the source is alone in motion towards the observer, the formula is given by:

[tex]f_o=f\frac{v}{v-v_s} \\\\Where:\\\\v_s=1220km/h\approx 338.8888889m/s\\v=342m/s\\f=3270Hz[/tex]

Therefore:

[tex]f_o=(3270) \frac{342}{342-338.8888889} = 359466.42Hz[/tex]

A leaf floating down from a tree is an example of an object in free fall.
A. True
B. False

Answers

Answer:

its false

Explanation:

because if an leaf floats down from a tree it is not considered an object for a free-fall

It’s going to be false

For the different values given for the radius of curvature RRR and speed vvv, rank the magnitude of the force of the roller-coaster track on the cart at the bottom of each dip. Rank from largest to smallest. To rank items as equivalent, overlap them.
A) R = 60m v = 16 m/s
B) R = 15m v = 8m/s
C) R = 30m v = 4m/s
D) R = 45m v = 4m/s
E) 30m v = 16 m/s
F) R = 15m v =12 m/s

Answers

Explanation:

The force of the roller-coaster track on the cart at the bottom is given by :

[tex]F=\dfrac{mv^2}{R}[/tex], m is mass of roller coaster

Case 1.

R = 60 m v = 16 m/s

[tex]F=\dfrac{(16)^2m}{60}=4.26m\ N[/tex]

Case 2.

R = 15 m v = 8 m/s

[tex]F=\dfrac{(8)^2m}{15}=4.26m\ N[/tex]

Case 3.

R = 30 m v = 4 m/s

[tex]F=\dfrac{(4)^2m}{30}=0.54m\ N[/tex]

Case 4.

R = 45 m v = 4 m/s

[tex]F=\dfrac{(4)^2m}{45}=0.36m\ N[/tex]

Case 5.

R = 30 m v = 16 m/s

[tex]F=\dfrac{(16)^2m}{30}=8.54m\ N[/tex]

Case 6.

R = 15 m v =12 m/s

[tex]F=\dfrac{(12)^2m}{15}=9.6m\ N[/tex]

Ranking from largest to smallest is given by :

F>E>A=B>C>D

A 12-V battery is connected to an air-filled capacitor that consists of two parallel plates,
each plate has an area of 7.60 cm2
. The separation between the plates of the capacitor is d =
0.30 cm. (Assume the electric field between the plates to be uniform).
a. Draw the situation.
b. Find the magnitude of the electric field between the plates.
Now, a proton (q = 1.6 x10-19 C) is released from rest at the positive plate of the capacitor.
c. Calculate the electric potential energy gained by the proton just before it touches the negative
plate.
A slab of Teflon of dielectric constant k =2.1 is then inserted between the plates of the
capacitor.
d. What is the new capacitance of the capacitor?
e. Calculate the change in the total energy stored in the capacitor before and after inserting the
dielectric slab.

Answers

Answer:

E = 4000 V / m

U = 1.92*10^-18 J

C' = 4.71 pF

1.2 times greater with di-electric

Explanation:

Given:-

- The potential difference between plates, V = 12 V

- The area of each plate, A = 7.6 cm^2

- The separation between plates, d = 0.3 cm

- The charge of the proton. q = 1.6*10^-19 C

- The initial velocity of proton, vi = 0 m/s

Solution:-

- The electric field ( E ) between the parallel plates of the air-filled capacitor is determined from the applied potential difference by the battery on the two ends of the plates.

- The separation ( d ) between the two plates allows the charge to be stored and the Electric field between two charged plates would be:

                          E = V / d

                          E = 12 / 0.003

                          E = 4,000 V/m ... Answer

- The amount of electrostatic potential energy stored between the two plates is ( U ) defined by:

                         U = q*E*d

                         U = (1.6 x10^-19)*(4000)*(0.003)

                         U = 1.92*10^-18 J  ... Answer

- The electrostatic energy stored between plates is ( U ) when the proton moves from the positively charges plate to negative charged plate the energy is stored within the proton.

- A slab of di-electric material ( Teflon ) is placed between the two plates with thickness equal to the separation ( d ) and Area similar to the area of the plate ( A ).

- The capacitance of the charged plates would be ( C ):

                        C = k*ε*A / d

Where,

            k: the di-electric constant of material = 2.1

            ε: permittivity of free space = 8.85 × 10^-12

- The new capacitance ( C' ) is:

                      C' = 2.1*(8.85 × 10^-12) *( 7.6 / 100^2 ) / 0.003

                      C' = 4.71 pF

- The new total energy stored in the capacitor is defined as follows:

                     U' = 0.5*C'*V^2

                     U' = 0.5*(4.71*10^-12)*(12)^2

                     U' = 3.391 * 10^-10 J

- The increase in potential energy stored is by the amount of increase in capacitance due to di-electric material ( Teflon ). The di-electric constant "k" causes an increase in the potential energy stored before and after the insertion.

- Hence, the new potential energy ( U' ) is " k = 2.1 " times the potential energy stored in a capacitor without the di-electric.

                     

What is kinetic energy

Answers

Answer:

Kinetic energy is the energy of motion

Answer:

Energy which a body possesses by virtue of being in motion

Explanation:

That the electric field is uniform between the electrodes means that the electric field lines: A.are more closely spaced at the positive electrode than at the negative one. B.intersect halfway between the electrodes. C.are more closely spaced at the negative electrode than at the positive one. D.are equally spaced at both electrodes and between them.

Answers

Answer: Option D.

Are equally spaced at both electrodes and between them.

Explanation:

An electric field is the region that surrond electrically charged particle which may cause attraction or repelling of the particle due to the force that is exerted on it.

The electric field between two electrodes due to electrostatic forces exist in the air and there is an increase of external voltage is added to it. Electric field are uniform between electrodes which signify that the electric field lines are evenly spaced at both electrodes and between them.

A model rocket is fired straight up from the top of a 45-m-tall building. The rocket has only enough fuel to burn for 4.0 s. But while the rocket engine is burning fuel, it produces an upward acceleration of 55 m/s2. After the fuel supply is exhausted, the rocket is in free fall and just misses the edge of the building as it falls back to the ground. Ignoring air resistance, calculate (a) the height above the ground and the velocity of the rocket when its fuel runs out; (b) the maximum height of the rocket; (c) the time the rocket is in the air; and (d) the rocket's velocity the moment before it hits the ground.

Answers

Answer:

a)y = 485 m ,  v = 220 m / s , b)  y = 2954.39 m , c)   t_total = 51 s ,

d) v = 240.59 m / s

Explanation:

a) We can use vertical launch ratios for this exercise

the speed of the rocket the run out the fuel is

        v = v₀ + a t

the rocket departs with initial velocity v₀ = 0

        v = a t

        v = 55 4

        v = 220 m / s

the height at this point is

        y = y₀ + v₀t + ½ a t²

        y = y₀ + 1/2 a t²

        y = 45 + ½ 55 4²

        y = 485 m

b) the maximum height of the rocket is when its speed is zero

for this part we will use as the initial speed the speed at the end of the fuel (v₀´ = 220 m / s) and the height of y₀´ = 485 m

        v² = v₀´² + 2 g (y-y₀´ )

         0 = v₀´² + 2 g (y-y₀´ )

         y = y₀´ + v₀´² / 2g

         y = 485 + 220 2/2 9.8

         y = 2954.39 m

c) the time that the rocket is in the air is the acceleration time t₁ = 4 s, plus the rise time (t₂) plus the time to reach the ground (t₃)

let's calculate the rise time

           v = v₀´- g t

           v = 0

            t₂ = v₀´ / g

            t₂ = 220 / 9.8

            t₂ = 22.45 s

Now let's calculate the time it takes to get from this point (y₀´´ = 2954.39 m) to the floor

           y = y₀´´ + v₀´´ t - ½ g t²

           0 = y₀´´ - ½ g t²

          t = √ (2 y₀´´ / g)

          t = √ (2 2954.39 / 9.8)

          t = 24.55 s

the total flight time is

       t_total = t₁ + t₂ + t₃

       t_total = 4 + 22.45 + 24.55

        t_total = 51 s

d) the veloicda right now

       v = vo + g t

       v = 9.8 24.55

       v = 240.59 m / s

ASAP pls answer right I will mark brainiest . All I know is 4. Is A

Answers

Answer:

Q1: B.2 Q2: B.Waxing crescent Q3: A.Waxing Gibbous

Explanation:

A 60 cm diameter potter's wheel with a mass of 30 kg is spinning at 180 rpm. Using her hands, a potter forms a 14 cm-diameter pot that is centered on and attached to the wheel. The pot's mass is negligible compared to that of the wheel. As the pot spins, the potter's hands apply a net frictional force of 1.3 N to the edge of the pot. If the power goes out, so that the wheels motor no longer provides any torque, how long will it take the wheel to come to a stop? You can assume that the wheel rotates on frictionless bearings and that the potter keeps her hands on the pot as it slows.

Answers

Answer:

It will take the wheel 278.9 s to come to a stop

Explanation:

Mass of the potter's wheel, M = 30 kg

Diameter of the potter's wheel, d₁ = 60 cm = 0.6 m

Radius, r₁ = d/2 = 0.6/2

r₁ = 0.3 m

The moment of inertia of the wheel, [tex]I = 0.5Mr_1^{2}[/tex]

[tex]I = 0.5*30*0.3^{2}\\I = 1.35 kg.m^2[/tex]

d₂ = 14 cm = 0.14 m

r₂ = 0.14/2 = 0.07 m

Angular velocity, [tex]\omega = 180 rpm[/tex]

[tex]\omega = \frac{180*2\pi }{60} \\\omega = 18.85 rad/s[/tex]

Frictional Force, F = 1.3 N

The torque generated:

[tex]\tau = F*r_{2}\\\tau = 1.3*0.07\tau = 0.091 Nm[/tex]

Torque can also be calculated as:

[tex]\tau = I \alpha\\\tau = I \frac{\omega }{t} \\0.091 = 1.35*\frac{18.8 }{t} \\t = (18.8*1.35)/0.091\\t = 278.9 s[/tex]

The time taken for the potter's wheel to come to a stop is 280 s.

The given parameters;

diameter of the potter's wheel, d = 60 cm radius of the wheel, r = 30 cm = 0.3 mangular speed, ω = 180 rpm

The momentum of inertia of the potter's wheel is calculated ;

[tex]I = \frac{1}{2} Mr^2\\\\I = (0.5)(30)(0.3)^2\\\\I = 1.35 \ kgm^2[/tex]

The angular speed of the potter's wheel is calculated as follows;

[tex]\omega = 180 \ \frac{rev}{\min} \ \times \ \frac{2\pi \ rad}{1 \ rev} \times \frac{1\min}{60 \ s} \\\\\omega = 18.85 \ rad/s[/tex]

The time taken for the wheel to come to a stop is calculated as;

[tex]Fr = I \alpha \\\\Fr= I \times \frac{\omega}{t} \\\\t = \frac{I \omega }{Fr} \\\\[/tex]

d = 14 cm, r = 7 cm = 0.07 m

[tex]t = \frac{1.35 \times 18.85}{1.3 \times 0.07} \\\\t = 279.6 \ s\\\\t\approx 280 \ s[/tex]

Thus, the time taken for the potter's wheel to come to a stop is 280 s.

Learn more here:https://brainly.com/question/12473935

A spherical shell contains three charged objects. The first and second objects have a charge of −18.0 nC−18.0 nC and 38.0 nC38.0 nC , respectively. The total electric flux through the shell is −218 N⋅m2/C−218 N⋅m2/C . What is the charge on the third object?

Answers

Answer:

q3 = 21.9 nC

Explanation:

By the Gauss theorem you have that the electric flux in a Gaussian surface is given by:

[tex]\Phi_E=\frac{Q}{\epsilon_o}[/tex]      (1)

ФE: electric flux = -218Nm^2/C

Q: net charge inside the Gaussian surface

εo: dielectric permittivity of vacuum = 8.85*10^-12 C^2/(Nm^2)

You can consider the spherical shell as a Gaussian surface. Then, the net charge inside the surface is:

[tex]Q=-18.0nC+38.0nC+q_3[/tex]     (2)

where charge q3 is unknown charge of the third object:

You replace the equation (2) into the equation (1), and you solve for q3:

[tex]\epsilon_0 \Phi_E=-18.0*10^{-9}C+38.0*10^{-9}C+q_3\\\\\epsilon_0 \Phi_E=20*10^{-9}C+q_3\\\\q_3=(8.85*10^{-12}C^2/(Nm^2))(-218Nm^2/C)-20*10^{-9}C\\\\q_3=2.19*10^{-9}C=21.9nC[/tex]

hence, the charge of the third object is 21.9 nC

A 80-kg base runner begins his slide into second base when he is moving at a speed of 3.7 m/s. The coefficient of friction between his clothes and Earth is 0.70. He slides so that his speed is zero just as he reaches the base.A 45-kg pole vaulter running at 11 m/s vaults over the bar. Her speed when she is above the bar is 1.1 m/s. Neglect air resistance, as well as any energy absorbed by the pole, and determine her altitude as she crosses the bar.

Answers

Answer:

  the vaulter has a height of 6.112 meters

Explanation:

Base runner: no question content.

__

Pole vaulter:

Initial kinetic energy* is ...

  KE = (1/2)mv^2 = (1/2)(45 kg)(11 m/s)^2 = 2722.5 J

Above the bar, her kinetic energy is ...

  KE = (1/2)mv^2 = (1/2)(45 kg)(1.1 m/s)^2 = 27.225 J

Then the amount of kinetic energy converted to potential energy is ...

  2722.5 J -27.225 J = 2695.275 J

This corresponds to a change in height of ...

  PE = mgh

  2695.275 J = (45 kg)(9.8 m/s^2)h

  h = 2695.275/(45·9.8) m = 6.112 m

Her altitude above the bar is 6.112 meters.

_____

* Here, we use the traditional equations for kinetic and potential energy, which use "m" to represent mass. When we fill in the numbers, we attach units to the numbers in which "m" represents "meters". We trust you can sort this without confusion.

What is the difference between reflection and refraction

Answers

Answer:

Reflection is when light bounces off an object, while refraction is when light bends while passing through an object.

Explanation:

I just learned about this 2 weeks ago actually.

How long does it take a car travelling at 60 m.p.h to cover 5 miles?

Answers

Answer:

Time = 5 minutes

Answer:

2minutes per mile

Explanation:

Not sure if it helps

Describe how heat transfer occurs when you

place your hand in a sink full of hot water.

Answers

Answer:

If one places ones's hands into a sink full of hot water, heat is transferred from the hot water to the hands. Heat only flows when there is a temperature gradient, i.e when there is a difference in temperature between a hot and a cold body. Heat is always transferred from a hot body to a cold body and never the reverse in a normal system.

At the boundary of the hand and water, heat transfer is by conduction between the hot water molecules and the molecules of the hands. This heat is then further transferred to the internal body organs and body fluid through either convection or conduction. This heat transfer is maintained until both the water and the hands are at the same temperature, assuming the owner is able to withstand the heat.

A 2300 kg truck has put its front bumper against the rear bumper of a 2500 kg SUV to give it a push. With the engine at full power and good tires on good pavement, the maximum forward force on the truck is 18,000 N. What is the maximum possible acceleration the truck can give the SUV?

Answers

Answer:

Acceleration a = 3.75 m/s^2

Explanation:

Given that

Mass M1 = mass of the truck = 2300kg

Mass M2 = mass of the SUV = 2500kg

Force applied F = 18000N

From Newton second law,

F = ma

Where a = acceleration

We must consider the entire mass involved in the system. Therefore,

F = (M1 + M2)a

Make a the subject of formula

a = F/(M1 + M2)

Acceleration a = 18000/( 2300 + 2500)

Acceleration a = 18000/ 4800

Acceleration a = 3.75 m/s^2

A man paddles a canoe in a long, straight section of a river. The canoe moves downstream with constant speed 4 m/s relative to the water. The river has a steady current of 2 m/s relative to the bank. The man's hat falls into the river. Seven minutes later, he notices that his hat is missing and immediately turns the canoe around, paddling upriver with the same constant speed of 4 m/s relative to the water. How long does it take the man to row back upriver to reclaim his hat

Answers

Answer:

7 minutes

Explanation:

From the question, the flow of the river applies equally to both the hat and the canoe. The best way to approach this problem is to look at it from a perspective that follows the water, and ignores the bank.

Hence, the water and the hat are stationary, and the man paddles away from the hat and then paddles back.

Now, the hat is at rest and relative to the water and the canoe always travels at a speed of 4 m/s relative to the water.

We are told that it takes 7 minutes for the man to travel away from the hat.

Since he is travelling at a constant speed, it will therefore take same time of 7 minutes for him to return.

So, it will take 7 minutes for the man to row back upriver to reclaim his hat.


A learner driver travels at a speed of 3km/h for an hour and a half. What distance does it travel?

Answers

Answer:

distance covered is 4.5km or 1.25m

Explanation:

GIVEN DATA:

SPEED=v=3km/h

TIME=t=1.5h

TO FIND:

DISTANCE COVERED=d=?

SOLUTION:

As we know that

speed=distance covered /time taken

here we have to find distance

speed×time taken=distance covered

3km/h×1.5h=distance covered

4.5km=distance covered or in international system of unit the answer is 1.25m

An unstable particle is created in the upper atmosphere from a cosmic ray and travels straight down toward the surface of the earth with a speed of 0.99537 c relative to the earth. A scientist at rest on the earth's surface measures that the particle is created at an altitude of 40.0 km .
As measured by the scientist, how much time does it take the particle to travel the 40.0 km to the surface of the earth?

Answers

Answer:

Explanation:

Velocity relative to earth = .99537 c

= .99537 x 3 x 10⁸ m /s

= 2.98611 x 10⁸ m /s

distance relative to earth = 40 km = 40 x 10³ m .

Time measured by scientist

= 40 x 10³ /  2.98611 x 10⁸

= 13.395 x 10⁻⁵ s

= 134 μs.

The planet Earth travels in a circular orbit at constant speed around the Sun. What is the net work done on the Earth by the gravitational attraction between it and the Sun in one complete orbit

Answers

Answer:

WT =  3.32*10^34 J

Explanation:

The work done by the gravitational attraction between the Sun and the Earth in one complete orbit of the Earth can be calculated by using the following formula:

[tex]W_T=\int F_g dr[/tex]  (1)

Fg: gravitational force between Sun and Earth

The gravitational force is given by:

[tex]F_g=G\frac{m_sm_e}{r^2}[/tex]  (2)

G: Cavendish's constant = 6.674*10^-11 m^3 kg^-1 s^-2

ms: mass of the sun = 1.989*10^30 kg

me: mass of the Earth = 5.972 × 10^24 kg

r: distance between Earth and Sun, this value is a constant r = R = 149,597,870 km

You replace the formula (2) in (1):

[tex]W_T=\int G\frac{m_sm_e}{R^2}dr=G\frac{m_sm_e}{R^2}\int dr\\\\W_T=G\frac{m_sm_e}{R^2}(2\pi R)=2\pi G\frac{m_sm_e}{R}[/tex]

Next, you replace the values of all variables and solve obtain WT:

[tex]W_T=2\pi (6.674*10^{-11}m^3kg^{-1}s^{-2})\frac{(1.989*10^{30}kg)(5.972*10^{24}kg)}{(149597870*10^3 m)}\\\\W_T=3.32*10^{34}J[/tex]

hence, the work done on the Earth, in one orbit, is 3.32*10^34 J

Dock diving is a great form of athletic competition for dogs of all shapes and sizes. Sheba, the American Pit Bull Terrier, runs and jumps off the dock with an initial speed of 8.62 m/s at an angle of 28° with respect to the surface of the water. (Assume that the +x axis is in the direction of the run and the +y axis is up.) (a) If Sheba begins at a height of 0.85 m above the surface of the water, through what horizontal distance does she travel before hitting the surface of the water? m

Answers

Answer:

62.4m

Explanation:

a) Horizontal distance traveled = x = [tex]v_x[/tex] * t

where,

[tex]v_x[/tex]  = horizontal velocity

and t = time in the air)

Time in the air t can be solved using the equation for y:

[tex]i_y=y_o+v_o_yt - 0.5gt^2[/tex]

where, [tex]y_o[/tex] = initial height i.e 0.85 m

[tex]v_o_y[/tex] = initial vertical velocity

and g = 9.8 m/s^2

When y = 0, the dog has hit the water.

So set y = 0 and solve for t.  

[tex]v_o_y[/tex] = 8.62 m/s [tex]\times[/tex] (sin 28) = 4.04 m/s

0 = 0.85 m + (4.04 m/s)t - 0.5gt²  

0.5t²-4.04t-0.85  

Solve this quadratic formula for t: the solutions are t = 8.2 s and t = -0.2. Reject the negative solution, so t = 8.2 s.

How far does the dog travel horizontally in 9.2 s?

x = [tex]v_x[/tex] * t  = (8.62 m/s) [tex]\times[/tex] (cos 28) [tex]\times[/tex]  8.2 s = 62.4 m  

She travels the horizontal distance before hitting the surface of the water is 62.4m

What is projectile?

When an object is thrown at an angle from the horizontal direction, the object is said to be in projectile motion. The object which follows the projectile motion.

a) Horizontal distance traveled = x = V(x) * t

where, V(x)  is the horizontal velocity and t = time in the air

Time in the air t can be solved using the equation for y:

hy =yo + Voy x t - 1/2gt²

where,  yo= initial height i.e 0.85 m and Voy = initial vertical velocity

and g = 9.8 m/s^2

When y = 0, the dock has hit the water.

So set y = 0 and solve for t.  

Voy = 8.62 m/s x (sin 28) = 4.04 m/s

Substitute the values, we get time as

0 = 0.85 m + (4.04 m/s)t - 0.5gt²  

0.5t²-4.04t-0.85 =0

Solving the quadratic formula for t, we have

time t = 8.2 s and t = -0.2.

As time can't be negative, so, t = 8.2 s.

The horizontal distance is

x = Vo * t  = (8.62 m/s)  (cos 28)   8.2 s = 62.4 m  

Thus, she travels 62.4 m.

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A 1kw electric heater is switched on for ten minutes. how much heat does it produce​

Answers

H= P × t

1kW= 1000w

10 min = 600s

H= 1000×600=600,000J

=> 143.40kcal

The 5-lb collar is released from rest at A and travels along the frictionless guide. Determine the speed of the collar when it strikes the stop B. The spring has an unstretched length of 0.5 ft.

Answers

Answer:

Explanation:

Stiffness of spring k equal to 4 lb/ft.

Unstretched length of the spring L is equal to 0.5 feet.  

Weight of the collar W is 15lb

Radius of curvature of curve guide is 1 feet

length of vertical rod is 1.5 feet

Initial speed of collar when released from rest at A is 0 feet per seconds  

use the energy conservation equation

 [tex]P_A +K_A=P_B+K_B[/tex]

Estimate the potential energy , component as position B as below

[tex]P_A=Wh_1+\frac{1}{2} ks^2_1\\\\=5\times(1.5+1)+\frac{1}{2} \times 4 \times(1.5+1-0.5)^2\\\\=20.5lb.ft[/tex]

Estimate the kinetic energy , component as position A as below

[tex]K_A=\frac{1}{2} \frac{W}{g} V^2_1\\\\=\frac{1}{2} \frac{5}{32.2} \times0^2\\\\=0lb.ft[/tex]

Estimate the kinetic energy , component as position B as below

[tex]K_A=\frac{1}{2} \frac{W}{g} V^2_2\\\\=\frac{1}{2} \frac{5}{32.2} \times V^2_2\\\\=00777V^2_2[/tex]

Substitute 20.5lb- ft for [tex]P_A[/tex]

0.5lb-ft for [tex]P_B[/tex]

0lb -ft for [tex]K_A[/tex]

[tex]0.0777V_2^2 for K_B[/tex]

[tex]20.5+0=0.5+0.777V^2_2\\\\V^2_2=257.6\\\\V_2=16.05[/tex]

= 16.05ft/sec

Asap pls hurry will mark brainiest

Answers

#1. A. Waxing crescent.
#2. 1.
#3. C.
#4. C.

A 30-kg skater moving at 3 m/s overtakes a 35-kg skater moving at 1 m/s in the same direction and collides with her. The two skaters stick together. It’s final speed is 1.9 m/s. How much kinetic energy is lost? Round all your answers to one decimal place.

Answers

Answer:

The lost in kinetic energy is   [tex]KE_l = 125.5 \ J[/tex]

Explanation:

From the question we are told that

   The mass of the first skater is  [tex]m_1 = 30 \ kg[/tex]

    The speed of the first skater is  [tex]v_1 = 3 \ m/s[/tex]

     The mass of the second skater is [tex]m_2 = 35 \ kg[/tex]  

     The  speed of the second skater is  [tex]v_2 = 1 \ m/ s[/tex]

     The final speed of both skater are [tex]v_f = 1.9 m/s[/tex]

The initial kinetic energy of both skaters is mathematically represented as

     [tex]KE_i = \frac{1}{2}m_1 v_1^2 + \frac{1}{2}m_2 v_2^2[/tex]

substituting values  

    [tex]KE_i = \frac{1}{2} * 30 * 3^2 + \frac{1}{2} * 35 * 1^2[/tex]

     [tex]KE_i = 242.5 \ J[/tex]

The final kinetic energy of both skaters is mathematically represented as

       [tex]KE_f = \frac{1}{2} * (m_1 + m_2 ) v_f^2[/tex]

substituting values

      [tex]KE_f = \frac{1}{2} * (30 + 35 ) * 1.9^2[/tex]

      [tex]KE_f = 117 \ J[/tex]

The lost in kinetic energy is

      [tex]KE_l = 242.5 -117[/tex]

       [tex]KE_l = 125.5 \ J[/tex]

Where does the energy released in nuclear reactions come from

Answers

Answer:

Nuclear energy comes from tiny mass changes in nuclei as radioactive processes occur. In fission, large nuclei break apart and release energy; in fusion, small nuclei merge together and release energy.

I hoep that was helpful! Let me know:)

Explanation:

Where is the potential energy equal to zero?

Answers

Answer:

im sure your already past this but it's E.

Explanation:

This is because in this case potential energy is linear to height, which means that the higher the more potential energy.

Horizontal beam AB is 200 kg, 2.4 m long, and is welded at point A. The man is 80 kg and applies a tension of 300 N on the cable. Diameter of the pulley is 300 mm and BC = 300 mm. Determine:
(a) horizontal and vertical components of force at A,
(b) magnitude and direction of the moment supported at A.

Answers

Answer:

[tex]a)-3346.8\;N \\ b)-4937.04\;N-m[/tex]

Explanation:

a) - In Free-body diagram :

At point D, the free body diagram of a man :

[tex]D = Fn\\Fn=T+mg\\put\;values\;in\;it\\ .\;\;\;\;=300+(80)(9.81)=1084.8\;N[/tex]

[tex]Mg=200\times9.81=1962\;N[/tex]

[tex]\sum Fx=0\; where\; Ax=0[/tex]

[tex]\sum Fy=0\; where\; Ay-Mg-Fn-T=0[/tex]

Then, put the value in the equation.

[tex]Ay=3346.8\;N[/tex]

b)-

[tex]Ma=Mg(AE)+Fn(AD)+T=4937.04\;N-m[/tex]

PLZZZ HELP
Question 2 Multiple Choice Worth 2 points)
(04.05 LC)
Which of the following scenarios describe an object being acted on by a non-conservative force?
O Apuck hovers and glides across an air track at constant velocity.
A dishwasher was pulled up to a window by a rope using a pulley system.
O A feather falls from one end of a tube to the other inside a vacuum.
O A charged particle was pushed away by another charged particle.

Answers

Answer:

C

Explanation:

A feather falls from one end of a tube to the other inside a vacuum.

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