A 1600 kg car on a flat ground is moving 6.25 m/s. Its engine creates a 1150N forward force as the car moves 45.8m. What is its final KE?

Question

anonymous · Answer

$$intial  KE=\frac{ 1 }{2 }mv ^{2} = \frac{ 1 }{2 }*1600*6.25^{2}=31250J$$$$Enginework=F*d=1150*45.8=52670J$$$$finalKE=initialKE+Enginework=31250+52670=83920J$$

anonymous · Answer

thank you so much!

anonymous · Answer

How about: A 1210 kg rollercoaster car is moving 8.31m/s. Before entering the station, it rolls up a 2.26m hill. How fast is it moving then?

anonymous · Answer

this time first calculate car's initial KE and substract the PE required for 2.26m rise from it. this will give you present KE. from that calculate present speed... :)

anonymous · Answer

how do you calculate the present speed?