Question

A 2.3 kg box, starting from rest, is pushed up a ramp by a 10 N force parallel to the ramp. The ramp is 2.0 m long and tilted at 17â. The speed of the box at the top of the ramp is 0.80 m/s.

How much work does the force do on the system?What is the change in the kinetic energy of the system?

Answer 1

Answer: WD = 20J

K.E = 0.736J

Explanation: given that:

Mass m = 23kg

Force F = 10N

Length of the ramp = 2m

Velocity V = 0.8m/s

The work done by the force on the system will be

WF = F × D = 10 × 2.0 = 20 J

The change in the kinetic energy of the system

Since the box is initially at rest,

u = 0. Therefore

dKE = ½mv²

= 0.5 × 2.3 × 0.8 × 0.8

= 0.736 J