Chapter 11, Problem 53A

The rock has a mass of 1 kg. What is the mass of the measuring stick if it is balanced by a support force at the one-quarter mark?

To determine

To calculate: The mass of the measuring stick.

Answer to Problem 53A

The mass of the measuring stick if it is balanced by a support force at the one-quarter mark is 1kg.

Explanation of Solution

Introduction:

The point of an object of a system of objects to which the weighted relative positions are totally zero is considered as the center of mass. Under the influences of an external force, the center of mass describes the overall motion of the system.

Consider the figure shown below.

The rock that located at the one-quarter of its length to the left and stick’s weight which is at the center of mass, one-quarter of its length to the right, balances the stick. Thus, the mass of the stick should be 1kg to balances the rock.

Conclusion:

Thus, the mass of the measuring stick is 1kg.