Answer:
Step-by-step explanation:
Torque is defined as the product of force and the perpendicular distance from the application of force. 
It is a vector quantity. 
Torque = force x perpendicular distance 
To loosen a nut, if we increase the amount of distance, the torque is increased by applying a little amount of force and hence it is easy to open the nut. 
Thus, it is easy to open a nut by slipping one end of a long pipe over the wrench handle and pushing at the other end of the pipe so that the torque is more and the nut is loosen.