While sitting on a perfectly slick, frictionless surface, a 60kg person accelerated an 10 kg medicine ball at 4 m/s ^2 away from himself. What acceleration did the person have?

A 1500kg truck reached 40 m/s in 11s from rest. What force did the engine provide?

A bus with mass 7500kg applies its brakes and a negative force of 20000 N is applied. If the bus was traveling at 30 m/s, what was the stopping distance?
If the time in the question above was .06 s, what velocity would the person reach?

Please help me out!