A body of mass 6kg, initially moving with speed 12m/s, experiences a constant retarding force of 10 newtons for 3 seconds. Find the kinetic energy of the body at the end of this time.

Answer 1

F*time = change in momentum
10*3 = 6 (12-v2)
30 -72 = -6 v2
42/6 = v2 = 7m/s

KE = (1/2) 6 (49)

Answer 2

don't know sorry