Power as it relates to constant velocity but increasing speed

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SUMMARY

The discussion centers on the relationship between power, force, and velocity in physics, specifically using the equation P=Fv. It concludes that if the force required to maintain constant velocity does not depend on speed, the power remains constant as speed increases. However, when considering a car, the force increases with the square of the speed, leading to the conclusion that power required also increases with speed. Thus, the assumptions made by the participants are confirmed as correct.

PREREQUISITES
  • Understanding of basic physics concepts such as force, velocity, and power
  • Familiarity with the equation P=Fv
  • Knowledge of how force varies with speed in real-world scenarios
  • Basic grasp of vector quantities in physics
NEXT STEPS
  • Explore the implications of Newton's Second Law on power and velocity
  • Investigate how drag force affects power requirements in vehicles
  • Learn about the relationship between kinetic energy and power in motion
  • Study the effects of friction on force and power in mechanical systems
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Students of physics, automotive engineers, and anyone interested in the dynamics of motion and energy efficiency in vehicles.

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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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.)
 

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