Chapter 4, Problem 14STP

To determine

To explain: Three ways in which simple machines make work easier with an example of a machine that makes work easier in that way.

Explanation of Solution

Introduction:

A device that changes the direction of force or increases the motion from the work done on it is known as a machine. A machine can change the direction of force, can increase speed or increase force.

Three ways in which simple machines can make work easier are:

1. Increase speed: Machines like bicycles increase speed. A person can travel faster than a bicycle than on foot.
2. Change direction of force: Machines like wedge-shaped blade of the ax change the direction of the force applied. A downward force is exerted on the ax to split wood. This downward force is changed by the ax into outward force that splits the wood.
3. Increase force: Machines like car jack increase force. The upward force exerted on the car is greater than the downward force exerted on the handle.

Conclusion:

By reducing friction, a machine can be made more efficient. Friction can be reduced by adding lubricant, such as oil or grease, to surfaces that rub together.