1. ACCELERATION AND GRAVITY Unit 2; Chapter 2

2. WHAT IS GRAVITY? Definition: A force of attraction between things that have mass Anything that has mass, no matter how small, exerts gravity on other matter

3. HOW DOES GRAVITY WORK ON EARTH? Gravity constantly pulls you towards the center of the planet Keeps you from being flung into space Pulls objects above Earth’s surface, down, towards the ground For example: Skydivers As objects fall to the ground, they accelerate Acceleration on Earth due to gravity = 9.8 m/s 2

4. HOW IS WEIGHT RELATED TO GRAVITY? Question: There is a force of gravity between Earth and you and also between you and all of the objects around you. So when you drop a paper clip, why doesn’t it all toward you instead of toward Earth? Earth is more massive and has a greater gravitational pull on the paper clip Definition: Weight measures the force of gravity pulling downward on an object. If the force of gravity changes, weight changes Your weight on Earth is different from your weight on Mars

5. MASS AND ACCELERATION DUE TO GRAVITY Question: Which has a greater mass, a bowling ball or a basketball? So if you drop them at the same time from the same distance above ground which will hit the ground first? They will hit the ground at the same time…..why? The greater mass of the bowling ball makes it harder to move so if moves at the same rate as the basketball All falling objects accelerate at the same rate due to gravity (unless air resistance affects one object more than another)

7. GRAPHING CHANGES IN ACCELERATION Velocity-time graphs allow us to visualize changes in velocity (acceleration) A positive slope = positive acceleration A negative slope = negative acceleration (deceleration) A zero slope = zero acceleration