Question

A uniform bar weighing 40N and measuring 2cm is hinged at one end so that the unhinged end can move up and down. If it is held horizontally by a spring balance at 0.3m from the free, determine the reading of the spring balance

Answer 1

First, let's calculate the torque caused by the weight at the given distance from the hinged end of the bar.

Torque = Force x Distance
Torque = 40 N * 0.2 m
Torque = 8 Nm

Now we need to find how much force the spring balance is applying in order to keep the bar in equilibrium state. This is given by the equation:

Force = Torque / Distance
Force = 8 Nm / 0.3 m
Force = 26.67 N

So the reading of the spring balance is 26.67 N.