| A | B |
|---|
| Force equal mass | times acceleration |
| Equal and opposite | means that the action force and the reaction force have the same size but act in opposite direction |
| Action and reaction forces present when you sit on a chair | action force |
| In a force pair, the reaction and action forces affect the same object | False |
| When a ball falls off a ledge, gravity pulls the ball toward the Earth and also pulls Earth toward the ball | True |
| Why does it take longer for a large truck to stop than it does for a compact car | The truck has more momentum (speed). |
| Momentum | depends on the mass and velocity (speed) of an object. |
| Law of Conservation of Momentum | Anytime two or more objects interact they may exchange momentum but the total amount of momentum stays the same |
| Galileo proved Aristotle wrong | True-the mass of an object does not affect the rate at which it falls. |
| What does 9.8 m/s have to do with acceleration? | For every second that an object falls, the object's downward velocity (speed) increases by 9.8 m/s |
| Air resistance | affected by the size and shape of an object |
| Air resistance matches the force of gravity when the net force | equals zero (acceleration or force of gravity) |
| When an falling object stops accelerating, it has reached | terminal velocity |
| A sky diver experiences free fall | False |
| Free fall occurs because of high air resistence | False |
| An astronaut is weightless in space | False |
| Earth's gravity provides a _______ that keeps th moon in orbit | centrifugal |
| The projectile motion of a leaping frog has two components | horizontal and vertical |
| True | On Earth gravity gives thrown objects their own downward ventricular motion. |
| True | Ignoring air resistance of a thrown object never changes. |
