Pennies in Motion: Newton’s Law of Physics

Newton’s 1^st law of physics states that an object at rest will stay at rest, and an object in motion will stay in motion. This is an easy physics concept that can be taught to students of all ages. For example, when a bowling ball is rolled down a bowling alley, according to Newton, it would continue to roll until a force acted upon it, like when it crashes into the pins, or if it rolls over a rough spot on the alley. Often things continue to move until it is pushed back by another force, called gravity. This activity is a neat way to teach this principle of motion and allow students to experiment with different variables like changing the size of the coin, the size of the balloon, even the rate at which they spin the balloon. http://www.ck12.org/physics/Newtons-First-Law/

In this activity students will experiment with the principles of motion.

Materials:

Balloons

Pennies (other coins are optional)

Instructions:

Place a penny in the balloon before you blow the balloon up.
Blow the balloon up and tie the end to keep the air in.
Move the balloon in a circular motion to get the penny moving.
Using enough force (without popping the balloon) continue to move the balloon in a circular motion until the penny is spinning along the inside of the balloon.
When you stop moving the balloon, the penny should continue moving around the inside of the balloon.
Allow time for each child to try to get the penny to spin.

How It Works:

The penny begins moving because of the force and motion applied to it. The penny is not stopped by the inside of the balloon because there is no friction (or resistance) making the penny stop spinning. The penny is able to move in a circular pattern around the balloon because of centripetal force, which is a force that draws things into the center of a circle. This is force is greater than gravity, which is why the penny does not fall until, you stop spinning it and gravity takes over.

Teaching physics concepts to students may seem daunting especially if you are unfamiliar with physics concepts yourself. Here is another great physics website that can get you well on your way to feeling more comfortable with teaching physics-related ideas like Newton’s laws of motion.