The entrance to a private car park is protected by a boom, which closes the entrance as shown in the figure below. The boom can be made to balance by fixing a counterweight W a short distance (0.5 m) from the pivot on the main support.
a) If the weight of the boom alone, F, is 400 N, and acts 3.0 m from the pivot as shown, calculate the counterweight required for the boom to be balanced.
b) If the actual counterweight fitted to this boom was 2350 N:
i) what additional downward force must be applied by the car park attendant to lift the boom
ii) what will be the normal reaction, N, at the end support when the boom is resting on it?
c) Calculate the reaction force at the pivot when the counterweight is 2350 N and the other end of the boom is supported.
d) If the boom is replaced with a strong one of weight 470 N and the 2350 N counterweight is to be used again, where should the counterweight be fixed to exactly balance the boom.