Newton's First Law

Lesson Plan - Get It!

Audio:

Energy is defined as the ability to do work.

How energy is used, stored, and exerted is an important part of everyday life.

In this series, All About Energy and Motion, you will investigate Sir Isaac Newton's three laws of motion.

In the previous Related Lesson, found in the right-hand sidebar, you learned about the life and legacy of an English physicist who made some of the world's most significant contributions to the investigation of energy.

In your own words, explain three new facts you learned about Isaac Newton.

• What did you find most interesting about him?

In this lesson, you will compare energy at rest and energy in motion, and investigate whether energy can be transferred.

1. Print the worksheet The Energy of a Ball found in Downloadable Resources in the right-hand sidebar.
2. For this activity, you will need two round balls. It does not matter what type of balls you choose to use, but try to select balls that are about the same weight and size.
3. Follow the instructions on the worksheet and record your observations as you work.

What did you notice about the energy of the ball during each part of the activity? You should have made the following observations and conclusions:

• During Part 1, you should have observed that the ball remained stationary, because you did not roll it or move it. Because the ball was not moving, it probably appeared that it did not have any energy at all. In this position, the ball has potential, or stored, energy. Typically, it is said that an object at rest has potential energy because it has the potential to do work.

• During Part 2, you should have observed that the ball rolled when you applied force. The ball should have continued to roll until you stopped it or it hit an obstacle. When the ball is moving, it has kinetic energy, or energy in motion.

• In Part 3, you were investigating whether the moving ball could transfer its energy to the stationary ball. The moving ball had kinetic energy and the stationary ball had potential energy. When the moving ball struck the stationary ball, the moving ball should have slowed down and changed direction. At the same time, the stationary ball should have started moving. This reaction occurred because the ball with kinetic energy transferred some of its energy to the stationary ball (that had potential energy) when it struck the other ball.

The concepts you observed in this lesson are part of Newton's first law of motion.

The laws of motion describe how and why objects move. Newton's first law is sometimes referred to as the Law of Inertia. According to this law, an object in motion tends to stay in motion, and an object at rest tends to stay at rest; that is, unless the resting object is acted upon by an outside force.

Learn more about Newton's First Law of Motion with this video:

Let's continue learning about Newton's first law by watching the National Science Foundation's video Newton's First Law of Motion - Science of NFL Football (below). This video will help connect the law of inertia to something you are probably familiar with:

•  How did the activity you completed relate to Newton's first law?

 When you are ready, continue on to the Got It? section.