## 14 (a) Work = force X Distance

**The ability to do work or cause change is called energy.**So the wind has energy.

__When an object or living thing does work on another object, some of its energy is transferred to that object. You can think of work, then, as the transfer of energy. When energy is transferred, the object upon which the work is done gains energy. Energy is measured in joules—the same units as work.__

Work and Energy:Work and Energy:

The meaning of work: In scientific terms, you do work when you exert a force on an object that causes the object to move some distance. The amount of work you do depends on both the amount of force you exert and the distance the object moves. The amount of work done on an object can be determined by multiplying force times distance.

You can use the work formula to calculate the amount of work you do to lift a plant. When you lift an object, the upward force you exert must be at least equal to the object’s

To lift the plant, you would have to exert a force of 100 newtons. So the amount of work you do would be 100 newtons × 0.5 meter, or 50 N·m. When force is measured in newtons and distance in meters, the SI unit of work is the newton × meter (N·m). This unit is also called a joule (jool) in honor of James Prescott Joule, a physicist who studied work in the mid-1800s. One joule (J) is the amount of work you do when you exert a force of 1 newton to move an object a distance of 1 meter. You would have to exert 50 joules of work to lift the plant.

What is the SI unit for work?--------------------joule (J)

**Work = force X distance**You can use the work formula to calculate the amount of work you do to lift a plant. When you lift an object, the upward force you exert must be at least equal to the object’s

__. The distance you lift the plant is 0.5 meters. The amount of work you do on the plant can be calculated using the work formula.__**weight****Work**= force (**100 N**) X distance (**0.5 meters**)To lift the plant, you would have to exert a force of 100 newtons. So the amount of work you do would be 100 newtons × 0.5 meter, or 50 N·m. When force is measured in newtons and distance in meters, the SI unit of work is the newton × meter (N·m). This unit is also called a joule (jool) in honor of James Prescott Joule, a physicist who studied work in the mid-1800s. One joule (J) is the amount of work you do when you exert a force of 1 newton to move an object a distance of 1 meter. You would have to exert 50 joules of work to lift the plant.

What is the SI unit for work?--------------------joule (J)

**What is a Machine?****A machine is a device that allows you to do work in a way that is easier or more effective.**You may think of machines as complex gadgets with motors, but a machine can be quite simple. For example, think about using a shovel. A shovel makes the work of moving soil easier, so a shovel is a machine.