Select the choice that does NOT describe an acceleration .
А pedaling faster
B coasting
C turning a corner
D hitting the brakes
Answer:
Answer
b) Coasting does not dedcribe acceleration
In hookes law an exact law of physics or an approximation? Why?
The maximum energy a bone can absorb without breaking is surprisingly small. For a healthy human of mass 59 kg , experimental data show that the leg bones can absorb about 200 J . Part A From what maximum height could a person jump and land rigidly upright on both feet without breaking his legs
Answer:
0.35mExplanation:
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
What do feathers, fur, overcoats, and whale blubber all have in common?
A. They are all good conductors of heat.
B. They all generate heat.
C. They are all electrical conductors.
D. They are all heat insulators.
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.
Police at a crime scene find a ceramic mug shattered on the sidewalk. They want to determine the window from which the mug fell, and they decide to make a model of the fall. Which quantitiy would be an important boundary condition for this model?
the hardness of the sidewalk where the mug landed
the time of day when the incident occurred
the final speed of the mug
the initial height of the mug above the sidewalk
Answer:
Initial height
Answer:
A: the hardness of the sidewalk where the mug landed
Explanation:
did the quick check
Choose all the right answers.
Each new cell produced by mitosis:
is different
inherits all the traits from its parent
obtains new traits
is identical to the parent's structure
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!
In the Daytona 500 auto race, a Ford Thunderbird and a Mercedes Benz are moving side by side down a straightaway at
67.0 m/s. The driver of the Thunderbird realizes that she must make a pit stop, and she smoothly slows to a stop over a
distance of 250 m. She spends 5.00 s in the pit and then accelerates out, reaching her previous speed of 67.0 m/s after a
distance of 360 m. At this point how far has the Thunderbird fallen behind the Mercedes Benz, which has continued at a
constant speed?
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
Determine the average velocity of the cart during the time interval from frame 100100 to frame 124124. For all vector quantities, we’ll use the convention that right is positive and left is negative.
The video showing the movement of the cart during the time interval is gotten from the link;
https://mediaplayer.pearsoncmg.com/assets/_frames.true/frames.true_white_ruler
Answer:
V_avg = 1.8 m/s
Explanation:
From the video, the distance moved by the cart during the 24 frames is 18 cm or 0.18 m.
Now, the speed is at the rate of 240 frames per seconds.
Now, average velocity is given as;
V_avg = distance/time
Time = 24 frames/240 frames/s
Time = 0.1 s
Thus;
V_avg = 0.18/0.1
V_avg = 1.8 m/s
The first stage of a Saturn V space vehicle consumed fuel and oxidizer at the rate of 1.50 3 104 kg/s with an exhaust speed of 2.60 3 103 m/s. (a) Calculate the thrust produced by this engine. (b) Find the acceleration the vehicle had just as it lifted off the launch
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 ,
What is the mass of a cylinder of silicon (in units of grams) that is 4.00 cm in diameter and 10.55 cm long?
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
If the stars at the turnoff point in a star cluster have masses of about four solar masses, how old is the cluster
Answer:
age of the cluster is 3.125 × 10⁸ years
Explanation:
Given that;
stars at the turnoff point in a star cluster have masses of about 4 solar masses
Age of the cluster?
we know that the main sequence lifetime of a star in solar lifetime(t) is related to the mass of the star in solar masses(M). expressed as
ζ = M^(-5/2)
our M is 4, so we substitute
ζ = 4^(-5/2)
ζ = 0.03125 solar lifetime
now convert the lifetime of star cluster into years
ζ = 0.03125 solar lifetime × (10¹⁰ years / 1 solar lifetime)
ζ = 312,500,000 ≈3.124 × 10⁸ years
therefore age of the cluster is 3.125 × 10⁸ years
What is the magnitude of the upward thrust force (assumed constant)?Express your answer with the appropriate units
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]
In part A, the metal object was heated in water. If some of the hot water was transferred to the calorimeter along with the metal object, what effect would this have on the calculated value of the specific heat of the metal
Answer:
The calculated value of the specific heat capacity of the metal will be larger than the actual value
Explanation:
If some of the hot water is transferred to the Calorimeter along with the metal object whose specific heat is to calculated the effect will be that the calculated value of the specific heat of the metal will be larger than normal
this can be explained with the equation below
= heat transferred to liquid in which metal was / Δ T metal
where ΔTmetal < heat transferred to liquid
"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?"
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
An 8.5 kg bowling ball initially at rest is dropped from the top of a building. The ball hits the ground with an acceleration of 9.8 m/s2. Find the net force on the falling ball.
Answer:
The answer is 83.3 NExplanation:
The force acting on an object given it's mass and acceleration can be found by using the formula
force = mass × accelerationFrom the question we have
force = 8.5 × 9.8
We have the final answer as
83.3 NHope this helps you
A 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.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?c. How far, in meters, from the original location of the limb will the car be when it stops?
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.
PLEASE HELP
You finally got inside the school. You look outside and see the zombie still coming after you. He is walking at 0.5 m/s. How long will it take him to get to the school if he is 200 m away?
Answer:
400 seconds
Explanation:
Divide the total distance by the unit rate
200/0.5 = 400
400 seconds
Answer:
400 seconds
Explanation:
how many hydrogen atoms are needed to bond with carbon so that both fulfill the octet rule?
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)
A rocket blasts off and moves straight upward from the launch pad with
constant acceleration. After 3.0 seconds the rocket is at a height of 77
meters. What is the rocket's velocity at that time?
Calculate the energy stored in a spiral spring
of force constant is 800 N/m compressed by
1.2 m
Answer:
W=k[tex]x^{2}[/tex]/2 = 576 j
Explanation:
What is the instrument used to measure amount of substance?
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.
CAN ANYONE PLEASE HELP ME WITH THIS QUESTION THAT IS ABOVE PLEASE I REALLY NEED THE HELP I AM STRUGGLING PLEASE THANK YOU IF YOU ANSWER MY QUESTION I APPRECIATE IT
Answer:
D.
Explanation:
What value resistor will discharge a 2.60 μFμF capacitor to 20.0%% of its initial charge in 2.20 msms ? nothing Ω
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
5. A basketball is passed 15 m due West, then 20 m north. What is the total distance the
basketball travelled?
Answer:
35 meters
20+15=35
A car accelerates from rest to 95 km/h in 5 seconds, what is the average acceleration of the car in m/s2
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:
acceleration=?change of velocity= final velocity - initial velocity= 95 km/h - 0 km/h (because the car accelerates from rest)= 95 km/htime= 5 secondsFirst, 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]
If everything else remains the same, but the charges of two objects are each doubled, the electrostatic force between them will be __________ times what it was before.
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.
Aballisprojectedverticallyupwardswithaninitialvelocityofugoestoa
maximumheighthbeforecomingtoground.Whatisthevalueofh?
A 1.95 m length of wire is held in an east–west direction and moves horizontally to the north with a speed of 15.5 m/s. The vertical component of Earth's magnetic field in this region is 40.0 μT directed downward. Calculate the induced emf between the ends of the wire and determine which end is positive.
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].
A person weighing 200 pounds stands on snowshoes. If the area of each snowshoe is 400 square inches, the pressure on the snow is
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
. Explain what a flyback diode is and why such a device is often placed in parallel with the coil in a relay circuit
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.