Chapter 9, Problem 15A

In what two ways can a machine alter an input force?

To determine

The two ways in which a machine can alter an input force.

Answer to Problem 15A

It can be altered by changing the magnitude or the direction of application.

Explanation of Solution

Introduction:

The efficiency of a machine is given by,

  $\text{efficiency =}\frac{\text{useful output work}}{\text{total input work}}$

The efficiency of the machine can be changed by changing its input force and thereby input work. Now, there are two ways in which the input force can be altered. First, is by changing its magnitude. Second, by changing its direction.

For example: more input force will be needed to move a box on incline as compared to move it on the straight line.

Conclusion:

Hence, the input force to a machine can be altered and thereby its efficiency can be changed.