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.
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?
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)
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?