A cart of mass 20 kg, initially at rest, is pushed with a net force of 40 N on a flat surface. If the cart is pushed 5 m, what is the final kinetic energy (KE) ? What is the final velocity? (Assume no heat losses.)

Using the theorem of kinetic energy

1/2mVf² - 1/2mVi² = WF + Wp, Wp=0

WF = F. AB, AB=5m and F = 40N, m=20kg

so the final kinetic is KEf = 1/2mVf² = WF = F. AB = 40*5=200J

the final velocity is 1/2mVf² = 200, implies Vf = sqrt (20) = 2sqrt (5) m/s