Power as it relates to constant velocity but increasing speed

In summary, the power required to keep an object in motion with a constant velocity remains the same regardless of the speed of the object. However, in the case of a car, the power required to keep it moving with a constant velocity increases with the square of the car's speed. This is because the force required to keep the car moving also increases with the square of its speed. Therefore, the answer to question a is correct, but the answer to question b is different.
  • #1
student1984
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the questions I have are general questions regarding power and velocity

here are some relevant equations:
P=Fv

a) if the force required to keep an object in motion with a constant velocity does not depend on the speed of the object, does the power required to keep the object moving in at a constant velocity increase, decrease or remain the same with increasing speed?

b) in actuality, the force required to keep a car moving with a constant velocity increases in magnitude with the square of the car's speed. Does the power required to keep the car moving with a constant velocity increase, decrease or remain the same with increasing speed? How does this result compare with the answer to question a?

I'm assuming from that answer to part a is REMAIN THE SAME and part b is INCREASES WITH INCREASING SPEED.

am i correct in my assumptions?
 
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  • #2
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student1984 said:
the questions I have are general questions regarding power and velocity

here are some relevant equations:
P=Fv

a) if the force required to keep an object in motion with a constant velocity does not depend on the speed of the object, does the power required to keep the object moving in at a constant velocity increase, decrease or remain the same with increasing speed?

b) in actuality, the force required to keep a car moving with a constant velocity increases in magnitude with the square of the car's speed. Does the power required to keep the car moving with a constant velocity increase, decrease or remain the same with increasing speed? How does this result compare with the answer to question a?

I'm assuming from that answer to part a is REMAIN THE SAME and part b is INCREASES WITH INCREASING SPEED.

am i correct in my assumptions?
If the velocity is constant, then the speed must be constant also. (The velocity's magnitude and direction are both constant; speed is the magnitude of velocity, hence it is constant.)
 

1. What is power in relation to constant velocity but increasing speed?

Power is the rate at which work is done or energy is transferred. In the context of constant velocity and increasing speed, power refers to the amount of energy required to maintain the object's motion and increase its speed over time.

2. How does power affect an object's velocity and speed?

In the case of constant velocity, power does not directly affect an object's velocity. However, as speed increases, more power is required to maintain the object's motion and continue increasing its speed.

3. Can power be negative or zero in this scenario?

Yes, power can be negative or zero in this scenario. Negative power indicates that the object is losing energy and slowing down, while zero power means that no energy is being transferred and the object's speed is constant.

4. What factors affect the power needed for an object to maintain constant velocity and increase speed?

The main factors that affect power in this scenario are the mass of the object and the force acting upon it. A heavier object or a larger force will require more power to maintain its motion and increase its speed.

5. How is power calculated in this situation?

In this situation, power can be calculated by multiplying the force acting on the object by its velocity. This is known as the power formula: P = F x v. Alternatively, if the object's mass and acceleration are known, power can be calculated using the formula: P = m x a x v.

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