A ball is being rolled by a normal push of 1000N. it is opposed by friction which has a force of 0.3kN and air resistance which has a force of 23N. Calculate the resultant force.

677 N

Explanation:

Let F = normal push force = 1000 N, f = frictional force = 0.3 kN = 300 N and f' = air resistance = 23 N.

Since the frictional force and the air resistance are in the opposite direction the the normal push force, the resultant force R is

R = F - f - f'

= 1000 N - 300 N - 23 N

= 677 N