Newton’s Laws

Newton’s Laws of Motion There are many different kinds of motion. We experience some kind of motion every minute of every day. As complicated as motion is, there are only 3 laws that describe all motion!

These laws were discovered by Sir Isaac Newton. Conveniently, these laws are referred to as… Newton’s 1st Law Newton’s 2nd Law Newton’s 3rd Law.

Newton’s 1st Law The Law of Inertia Before we learn about Newton’s 1st Law, we need to understand inertia, matter, and mass.

Mass is the amount of matter an object has. Examples: Underline the thing with more mass, and circle the thing with more matter.

100kg lead ball 70kg Aluminum ball

Explanation of #5 Two identical empty balloons have the same amount of matter, so they have the same mass. When one of the balloons is filled with air, the filled balloon has more matter (Air is a kind of matter). Therefore, the filled balloon has a greater mass.

The more mass something has, the harder it is to change the way it is moving. Examples 1. It is easy to change the motion of a balloon moving at 10km/hr, but it is difficult to change the motion of a _________ traveling at 10km/hr. car

2. It is easy to change the motion of a rolling beach ball, but it is difficult to change the motion of a rolling __________________. bowling ball 3. It is easy to change the motion of a pencil sitting on a desk, but it is harder to change the motion of a _____________ sitting on a desk. book

Inertia = Resistance an object has to a change in its motion. Objects with more mass resist change in their motion more than objects with less mass. Inertia = Resistance an object has to a change in its motion.

Answer the following questions. Use the word “inertia” in your answer: 1. Why it is easy to change the motion of a balloon moving at 10km/hr, but it is difficult to change the motion of a car traveling at 10km/hr? The car has more inertia, so it is more difficult to change its motion.

2. Why it is easy to change the motion of a rolling beach ball, but it is difficult to change the motion of a rolling bowling ball? The bowling ball has more inertia, so it is more difficult to change its motion. 3. Why it is easy to change the motion of a pencil sitting on a desk, but it is harder to change the motion of a book sitting on a desk? The book has more inertia, so it is more difficult to change its motion.

4. Why is easy to change the motion of a ______________, but difficult to change the motion of a ___________________? pillow sack of pennies The sack of pennies has more inertia, so it is more difficult to change its motion.

5. Explain why the items in the following picture do not move when the table is pulled away very quickly. The items on the table have inertia. So when the table is pulled away quickly, the items resist a change in their motion, so they do not move to the left with the table.