Does Constant Power Result in Constant Acceleration for a Car?

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SUMMARY

The discussion centers on a car with a mass of 1000 kg that accelerates from rest using a constant mechanical power of 60 kW. The calculated speed after 5 seconds is 24.5 m/s, leading to an acceleration of 2.45 m/s². The participant confirms that the force exerted by the motor is 2450 N, derived from the relationship P = Fv. The conclusion drawn is that constant mechanical power does not result in constant acceleration due to the changing velocity affecting the force required for acceleration.

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  • Understanding of Newton's Second Law (F = ma)
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  • Familiarity with kinetic energy concepts (W = Kf - Ki)
  • Basic physics of motion and acceleration
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Homework Statement


Car, mass 1000kg, accelerates from rest in straight line using constant mechanical power of 60kW.
What is speed and acceleration after 5s.


Homework Equations


W = Kf - Ki
P= dE/dt


The Attempt at a Solution



I've already worked out that the speed will be 24.5m/s. What I'm really wondering is if a constant mechanical power results in a constant acceleration. Any help would be appreciated. Thanks.
 
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I attempted to do the following:

F = ma, but F is provided by the motor. Therefore, P = Fv
60 000W = 24.5 x F
F = 2450 N

2450N = 1000kg x a
a = 2.45m/s^2

Does this seem like a reasonable approach?
 

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