The tongs shown are used to grip an object For an input forc

The tongs shown are used to grip an object. For an input force of 20 lb. on each handle, determine the forces exerted on the object and the forces exerted on the pin at A.

Solution

Given force of 20lbs is applied on the end of the object. Let us assume that the load at the point B is b

We know that since the point A is in equilibrium, the moment about A is equal to zero. Hence

20*6 -b*2 = 0

b = 60 lb of force

Now, for the load at the pin at A, let us assume it to be a

We know that B is held at position without any motion which means that it too is in equilibrium. Hence, moment about B is also zero.

=> 20*8 + a*2 = 0

a = 80 lb of force in the direction opposite to the action of 20lb