Question

A box of mass 2kg is being pushed horizontally on a rough surface by a 20N force for 5m.Given that the friction between the box and the surface is 10N ,what is the gain in K.E?

Answer 1

Force applied, F = 20N

friction, f = 10N

Net force = F - f = 20-10 = 10N
_______________________
mass = 2kg

acceleration, a = net force/mass = 10/2 = 5 m/s^2

Given that Displacement, s = 5m

u = 0

we know that v^2 - u^2 = 2as

=> v^2 = 2×5×5 = 50

Kinetic energy = 1/2 mv^2 = 1/2 × 2 × 50 = 50 J

kinetic energy is 50J

Answer 2

Answer:

20j

Explanation: