A painter of weight 1000N stands 1.0m from the left-hand end of a uniform plank which is 5.0m long and weighs 800N. The plank is supported by two trestles each 0.5m from the opposite ends. Thre are two upward forces P and Q acting on the plank due to the trestles.

By taking moments about the left trestle, calculate the upward force exerted on the plank by the other trestle.

1 answer

P = 800N + 1000N(1.0m/5.0m) = 1000N