Question

a 35kg child has 200J of kinetic energy after riding her bike down a hill what was her speed in meters per second at the bottom of the hill

Answer 1

KE= 1/2 mv^2
Kinetic energy= 0.5 * (mass*velocity squared)

200J= 0.5* 35* (V^2)

Move things to the other side (make V the subject

200/(0.5*35)= V^2
V^2= 11.4

Square root 11.4:

V= 3.38 m/s

Hope this helps :)