Lesson Objective Define the role of gravitational forces in our solar system.

For there to be gravity… does there need to be air?

= YES = NO

Gravity- A force of attraction between two objects that depends on two things: mass and distance.

Gravity- A force of attraction between two objects that depends on two things: mass and distance. 1.) The larger the mass the greater the gravitation attraction. 2.) The closer the two objects the stronger the attraction.

1.) The larger the mass the greater the gravitation attraction. Which planet will have the strongest gravity?

Space is a vacuum, so…is there gravity in space?

Gravity- A force of attraction between two objects Yes, even in space there is gravity! Vacuum = absence of matter, NOT the absence of gravity

( ) His observations of the movement of objects on Earth led him to conclude that all objects accelerate as they fall.

weight – measure of the pull of gravity on a mass A B CD Activity is found on the “ Discover ” page, under the “ Einstein in space ” tab ; at the bottom.

Acceleration is the rate of change in velocity. When we are talking about the acceleration of a falling object it would be: “… an increase in speed over time”. Positive acceleration can result from an increase in speed. Negative acceleration, also called deceleration, results from a decrease in speed. Acceleration of a falling object is due to gravity. All objects fall at a constant rate, the only reason we see them falling different is due to other forces acting on the objects.

Simon is skydiving. What is Simon hoping will happen next? A.He continues to fall towards Earth at a terminal velocity of 9.8 m/s B.His acceleration towards Earth increases. C.His acceleration decreases due to his parachute deploying, increasing the air resistance. D. The atmosphere suddenly becomes a vacuum. Let’s Think About It!

Air resistance is caused by the friction between a falling object and the particles in air. The amount of air resistance a falling object experiences is based on the shape of the object and the speed at which it falls.

For there to be gravity… does there need to be air? = YES = NO

Key Concepts to Keep in Mind A vacuum is the absence of all matter including air. Gravity is affected by – mass – distance Objects fall at different rates due to opposing forces