F=ma Physics Olympiad Exam question 19: Constant power

[jerrylinew]

Homework Statement

A car has an engine which delivers a constant power. It accelerates from rest at time t = 0, and at t = t0 its acceleration is a0. What is its acceleration at t = 2t0? Ignore energy loss due to friction.

Homework Equations

P=W/t, W=Fd, F=ma

The Attempt at a Solution

substitute the last two equations into the first equation to get P=m*a*d/t=constant. m is always constant, so a*d/t = constant. I don't know what to do from here.

 

[kuruman]

Try also to use

P = (Kinetic energy)/Time

and see where that gets you.

 

[phever]

you should try and think what is constant and then try to apply that here.

try to equate constant values .

 

[zorro]

P=f*v=ma*v
Try differentiating this and see what you get (don't forget the product rule)

 

[Redbelly98]

Moderator's note:

Now that the OP has been given several hints, I urge people to refrain from giving further help until the OP responds.

Thank you for your cooperation.