Question

Problem 9

Answer 1

Given information

A stone hangs from the ceiling by a fine thread, and a part of the same thread hangs from under the stone.

 

a) If a person makes a sharp pull on a hanging thread, where is the thread likely to break: under or over the stone?

 

b) What if the person pulls slowly and steadily?

 

Newton's second law states that the acceleration of an object depends on two variables - the net force acting on the object and the mass of the object. The acceleration of an object depends directly on the net force acting on the object and is inversely proportional to the mass of the object.

Step-by-step explanation

Step 1.

Free body diagram for given problem is:

a) When the person pulls sharply, the force will be applied suddenly. When a large, sudden force is applied to the lower wire, the lower wire will have a greater tension than the top. Due to the inertia of the stone, the upper part of the string does not immediately experience a large force. So, the wire at the bottom must have more tension and will break first.

 

b) If the person pulls slowly and steadily, the tension in the string below increases. We assume that the stone is considered to be in equilibrium until the string breaks.