How long will it take an object that falls from rest to attain a velocity of 147 m/s?

Answer:

2 : 1

Explanation:

Given that The magnitude of the acceleration due to gravity on the surface of planet A is twice as great as on the surface of planet B. What is the ratio of the weight of mass X on the surface of planet A to its weight on the surface of planet B?"

Since the magnitude of the acceleration due to gravity on the surface of planet A is twice as great as on the surface of planet B. And

Weight W = mg

Mass is always constant

2g : g

The ratio of the weight of mass X on the surface of planet A to its weight on the surface of planet B will be:

2 : 1

Answer:

D. They are all heat insulators.

Explanation:

Those things mentioned above are examples of heat insulators. As a heat insulator, it helps to prevent the heat from leaving the body thereby keeping the body warm and risk free.Feathers in birds and overcoat in humans helps to keep the bodies of the wearer safe and warm during the cold season.

Answer:

Moles

Explanation:

Moles can be used to measure the quantity of any substance. A mole of water is a small mouthful; a mole of elephants is about the size of the planet Saturn.

Answer:

W=k[tex]x^{2}[/tex]/2 = 576 j

Explanation:

Answer:

Initial height

Answer:

A: the hardness of the sidewalk where the mug landed

Explanation:

did the quick check

Answer:

B and D

Explanation:

Answer:

It is B. inherits all the traits from its parent

And D. is identical to the parent's structure

Explanation:

Hope this helped have an amazing day!

Answer:

D.

Explanation:

Answer:

The average acceleration of the car is 5.2778 [tex]\frac{m}{s^{2} }[/tex]

Explanation:

The acceleration of an object is a magnitude that indicates how the speed of the object changes in a unit of time. That is, acceleration relates changes in velocity with the time in which they occur.

The expression for the calculation of the acceleration is:

[tex]acceleration=\frac{change of velocity}{time}[/tex]

In this case:

First, it is convenient to express the change in velocity in units of m/s, where 1 h = 3,600 s and 1 km = 1,000 m.

[tex]change of velocity= 95 \frac{km}{h} =95\frac{1,000 m}{3,600 s} =26.3889 \frac{m}{s}[/tex]

So, replacing in the definition of acceleration:

[tex]acceleration=\frac{26.3889\frac{m}{s} }{5 s}[/tex]

acceleration= 5.2778 [tex]\frac{m}{s^{2} }[/tex]

The average acceleration of the car is 5.2778 [tex]\frac{m}{s^{2} }[/tex]

Answer:

Explanation:

The force acting on an object given it's mass and acceleration can be found by using the formula

From the question we have

force = 8.5 × 9.8

We have the final answer as

Hope this helps you

Answer:5

Explanation:

5 right

Answer:

4

Explanation:

Carbon, with 4 electrons in its valence shell, will need another four electrons to fulfill the octet rule. Thus it needs to combine with 4 hydrogen atoms to form a stable compound called methane(CH4)

Answer:

[tex]\epsilon=1.2\times 10^{-3}\ V[/tex]

Explanation:

Given that,

Length of a wire, l = 1.95 m

Speed of the wire, v = 15.5 m/s

The vertical component of Earth's magnetic field in this region is 40.0 μT directed downward.

We need to find the induced emf between the ends of the wire and determine which end is positive. The induced emf for a wire is given by :

[tex]\epsilon=Blv\\\\\epsilon = 40\times 10^{-6}\times 1.95\times 15.5\\\\\epsilon=1.2\times 10^{-3}\ V[/tex]

So, the induced emf between the ends of the wire is [tex]1.2\times 10^{-3}\ V[/tex].

Answer:

Explanation:

Thrust produced = v dm / dt

v is speed of exhaust and dm / dt is rate at which mass of gas is being thrown out .

= 2.603 x 10³ x 1.503 x 10⁴

= 3.91 x 10⁷ N  ,

Answer:

0.5 pounds per square inches (ibs/in²)

Explanation:

The pressure of an object refers to the force it exerts per unit area i.e. F/a. In this question, the force, F, is created by the weight, W, of the snowshoe. Hence, pressure is calculated thus:

P = W/A

Where; P = Pressure (ibs/in²)

W = Weight of object (ibs)

A = surface area (in²)

In this question, weight = 200 pounds, Area = 400 square inches

Hence, pressure = 200/400

Pressure (P) = 2/4

Pressure (P) = 0.5 ibs/in²

Answer:

Explained below.

Explanation:

A flyback diode is simply defined as a diode that is connected across an inductor in order to eliminate the sudden spike in voltage that's seen across an inductive load when its supply current is unexpectedly reduced or interrupted. This sudden spike in voltage is known as flyback.

It's very important to place this flyback diode in parallel with the coil in a relay circuit because it allows current to pass through with minimal resistance thereby preventing flyback voltage from building up when power is disconnected.

Answer:

The minimum radius of the curve is 6125 m

Explanation:

Given;

speed limit of the highway, V = 90 km/h = 25 m/s

banking angle, θ = 45°

The minimum radius of the curve will be calculated by applying banking angle formula;

[tex]mg tan \theta = F_{centripetal \ force}\\\\mg tan \theta = \frac{mv^2}{r}\\\\ g tan \theta = \frac{v^2}{r}\\\\r = \frac{v^2}{ g tan \theta}\\\\r = \frac{(25)^2}{(9.8)(1)} \\\\r = 6125 \ m[/tex]

Therefore, the minimum radius of the curve is 6125 m

Answer:

309.02g

Explanation:

According to the information given in this question, the cylinder has the following:

Mass = ?

Length/height = 10.55cm

Diameter = 4.00cm

Volume of a cylinder = πr²h

Where; π = pie (3.142 or 22/7)

r = radius (cm)

h = height

Note that, radius = diameter/2

Hence, radius (r) = 4.00/2

r = 2.00cm.

V = πr²h

V = 22/7 × 2² × 10.55

V = 22/7 × 42.2

V = 928.4/7

V = 132.628cm³

Density = mass/volume

Hence, mass = density × volume

Where density of silicon is 2.33g/cm³

Mass = 2.33g/cm³ × 132.628cm³

Mass = 309.02g

Answer:

The value of resistor is 525.76 ohms

Explanation:

Given;

capacitance, C = 2.6 μF = 2.6 x 10⁻⁶ F

let the initial charge on the capacitor = Q₀

time , t = 2.2 ms = 2.2 x 10⁻³ s

The discharge of the capacitor is given by;

[tex]Q(t) = Q_oe^{-\frac{t}{RC} }[/tex]

Where;

Q(t) is the charge after 2.2ms = 20% of Q₀ = 0.2Q₀

[tex]Q(t) = Q_oe^{-\frac{t}{RC} }\\\\0.2Q_o = Q_oe^{-\frac{t}{RC} }\\\\0.2 = e^{-\frac{t}{RC} }\\\\ln(0.2) = -\frac{t}{RC}\\\\-1.6094 = -\frac{t}{RC}\\\\R = \frac{t}{1.6094C} \\\\R = \frac{2.2*10^{-3}}{1.6094*2.6*10^{-6}}\\\\R = 525.76 \ ohms[/tex]

Therefore, the value of resistor is 525.76 ohms

Answer:

400 seconds

Explanation:

Divide the total distance by the unit rate

200/0.5 = 400

400 seconds

Answer:

400 seconds

Explanation:

Answer:

A.) 37.8 m/s

B.) No

C.) 172 m

Explanation:

Given that  car accelerates in the +x direction from rest with a constant acceleration of a1 = 1.89 m/s^2 for t1 = 20 s. At that point the driver notices a tree limb that has fallen on the road and brakes hard for t2 s until it comes to a stop. Required:

a.) Write an expression for the car's speed just before the driver begins braking, v1.

Since the car accelerate from rest, initial velocity U = 0

Using first equation of motion

V1 = U + at

V1 = 1.89 × 20

V1 = 37.8 m/s

b.) If the limb is on the road at a distance of 550 meters from where the car began its initial acceleration, will the car hit the limb?

Using third equation of motion

V^2 = U^2 + 2as

37.8^2 = 0 + 2 × 1.89 × S

1428.84 = 3.78S

S = 1428.84 / 3.78

S = 378m

Since the limb is on the road at a distance of 550 meters from where the car began its initial acceleration, we can therefore conclude that the car will not hit the limb.

c. How far, in meters, from the original location of the limb will the car be when it stops?

550 - 378 = 172 m

The car will be 172 metres from the limb.

Complete Question

A helicopter of mass  [tex]1.40 *10^{3}[/tex] kg is descending vertically at 3.00 m/s. The pilot increases the upward thrust provided by the main rotor so that the vertical speed decreases to 0.450 m/s as the helicopter descends 5.00 m. What is the magnitude of the upward thrust force (assumed constant)?Express your answer with the appropriate units.

Answer:

The value is  [tex]F = 11257 \ N[/tex]

Explanation:

From the question we are told that

   The mass of the helicopter is  [tex]m = 1.40 *10^{3} \ kg[/tex]

   The initial descending speed is [tex]u= 3.00 \ m/s[/tex]

   The  descending speed after the upward thrust has been increased is [tex]v = 0.450 \ m/s[/tex]

    The  height when descending speed is [tex]v = 0.450 \ m/s[/tex]  is  [tex]s = 5.0 \ m[/tex]

Generally according to the kinematics equations

   [tex]v^2 = u^2 + 2(a)s[/tex]

Here a is the acceleration due to gravity plus the acceleration of the helicopter

So

    a  =  [tex]a = -g + a_h[/tex]

the negative sign is due to the fact that the direction of the plane is in the negative y axis

So

       [tex]v^2 = u^2 + 2(-g + a_h)s[/tex]

=>    [tex]0.45^2  =  3^2  + 2(-9.9 + a_h) * 5[/tex]

=>   [tex]a_h = \frac{-8.7975}{5} + 9.8[/tex]    

=>   [tex]a_h = 8.0405 \ m/s^2[/tex]    

Generally the thrust force is mathematically represented as

     [tex]F = m * a_h[/tex]

=> [tex]F = 1.40 *10^{3} * 8.0405[/tex]

=> [tex]F = 11257 \ N[/tex]

Answer:

945 m

Explanation:

First of all let's find the first acceleration before the first stop. We will use Newton's 3rd equation of motion;

v² = u² + 2as

a = (v² - u²)/2s

In this first motion, the initial velocity is given as u = 67 m/s, while the final velocity which is the stop is v = 0 m/s and the distance is s = 250 m

Thus;

a = (0² - 67²)/(2 × 250)

a = -4489/500

a = -8.978 m/s²

Now, to get the time spent for this 250 m distance, we will use Newton's 2nd law of motion;

s = ut + ½at²

Plugging in the relevant values;

250 = 67t + ½(-8.978)t²

250 = 67t - 4.489t²

4.489t² - 67t + 250 = 0

Using quadratic formula, we will arrive at;

t = 7.463 s

Now, we are told that she accelerates out, reaching her previous speed of 67.0 m/s after a distance of 360 m. Thus, let's calculate the time it took to accelerate after a distance of 360 m.

Since she stayed from rest in this phase, then initial velocity (u) = 0 m/s.

Like in the first phase, we can find the acceleration from;

a = (v² - u²)/2s

a = (67² - 0²)/(2 × 360)

a = 4489/720

a = 6.235 m/s²

Thus, we can find the time for this 360 m phase by using; s = ut + ½at², we have;

360 = 0 + ½(6.235)t²

Multiply through by 2 to get;

6.235t² = 720

t² = 720/6.235

t² = 115.477145

t = √115.477145

t = 10.746 s

We are told that she spends 5 s in the pit. Thus;

Total time is;

t_total = 7.463 + 5 + 10.746

t_total = 23.209 s

Distance covered by the Mercedes Benz = 67 × 23.209 = 1555 m

Total distance covered by Thunderbird = 250 + 360 = 610 m

Thus, distance of Thunderbird behind Mercedes Benz is = 1555 - 610 = 945 m

Answer:The ampere is unique in that it uses the base unit of time (t) in its definition (second). All other electrical and magnetic units (such as voltage, power, and magnetic flux) use various combinations of base units in their definitions and are called derived units.

Explanation:

Answer:

Answer

b) Coasting does not dedcribe acceleration

Answer:

c

Explanation:

Answer:

Exercise can reduce pain, relieve stress, and increase energy.Explanation:

Answer:

Explanation:

In this problem we want to solve for the height given the potential energy

the potential energy is the energy possessed  by a body by virtual of it position.

given data

mass m=59kg

PE(potential energy)= 200J

Height h=?

assuming g=9.81,/s^2

we know that the expression for potential energy is

PE=mgh

substituting we have

200=59*9.81*h

200=578.79h

divide both sides by 578.79

h=200/578.79

h=0.35m

Therefore the height is 0.35m

Answer:

Four times

Explanation:

The electrostatic force between the two charges is given by :

[tex]F=\dfrac{kq_1q_2}{d^2}[/tex]

d is the distance between two charges

k is electrostatic constant

When both charges are doubled, [tex]q_1'=2q_1\ \text{and}\ q_2'=2q_2[/tex], new force is given by :

[tex]F'=\dfrac{kq_1'q_2'}{d^2}\\\\F'=\dfrac{k(2q_1)(2q_2)}{d^2}\\\\F'=4\times \dfrac{kq_1q_2}{d^2}\\\\F'=4F[/tex]

So, the electrostatic force between them will be four times what it was before.