Newton’s first law of motion

Newton’s first law states that an object will travel in a straight line at a constant speed unless a force is applied. Gravity is a force that can cause objects to travel in curved lines, and the stronger the gravity, the more strongly objects are pulled off the straight line trajectory. The gravity pulling towards the Sun keeps the planets in our Solar System in their orbits.

Related resources:

• Lift-off – article

• Gravity and satellite motion – article

• Launching satellites – article

Transcript

Gravity is a force that can cause objects to travel in curved lines, and the stronger the gravity, the more strongly objects are pulled off of the straight line trajectory.

Demonstrate how a massive object exerts a force that affects the motion of nearby objects by rolling a ping pong ball across a gravity well.

Place a heavy ball on the gravity well and roll the ping pong ball again.

Experiment by using a heavier ball to represent a more massive object.