Question

A 20 kg wagon is pulled along the level ground by a rope inclined at 30 deg above horizontal. A frictional force of 30 N opposes the motion, how large is the pulling force if the wagon is accelerating at the rate of 0.40m/s2?

Answer 1

F cos 30 - 30 = m a = 20 * 0.40
so
F = [ 30 + 8 ] / 0.866