Hi! I have some questions from a study guide in my physics class, and they give me the answer, but I have to show how to get the answer. I did most of them, but need help with these. Here is problem #3:

Question

A 30 kg kid on rollerskates is being pushed by his mom with a force of 10 N. If he starts from rest, how fast will he be moving after she pushes him 4.0 m? (1.63 m/s)

Answer 1

F=ma=mv²/2s
v=sqrt(2Fs/m)