Constant Power

A constant direction force delivers a constant power of 45.0 W to an 8.00-kg mass which is
initially moving in the direction of the force. At t = 0 s, the force is 5.00 N.
Calculate the speed of the mass after 4.00 s.

I've tried to do several different things, however I believe you need to integrate. My intregration skills are really weak, so please don't assume I'll know what you're doing if you skip alot of steps.

Thanks.
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 Recognitions: Homework Help Welcome to PF. You're in luck. You won't need to integrate. But you will need to understand what power is. Like what units is power expressed in?
 Kg m^2/s^3 Few more points would be helpful. Thanks

Recognitions:
Homework Help

Constant Power

OK and how is power related to Force?

Power = Force times ...?
 velocity.. however unfortunately the answer is not 9 m/s. The other information is needed to solve this.. as the force isn't the same throughout.. (it's 5.00 N only at t = 0 s)
 Recognitions: Homework Help You are jumping ahead a bit. The 9 m/s is the speed at t=0 however. Now think about what is a watt? A Joule/sec perhaps? And how many seconds? So how many Joules were added to the energy of the mass? ... And how many joules of energy did the mass have at t=0? And added together as Kinetic energy how fast does that mean the mass is going?
 Ahh thanks alot man.. appreciate it.