1. Forces

2. What is it?
A force is a push or a pull on an object Examples: Pushing a shopping cart, pulling a sled Types of Force: Balanced: forces are equal in magnitude an opposite in direction Unbalanced: forces are unequal in magnitude

3. Gravity Vs. WEighT
Gravity: inward force toward the center of an object Apply: Gravity depends on mass and acceleration; larger objects have more mass and therefore more gravitational pull Ag = 9.8 m/s2
Weight: The amount of force applied onto a mass Apply: Objects with more mass will have more weight Fw=mag

4. Air resistance and Mass
Amount of matter in an object
Does not change
Air Resistance
Depends on surface area and velocity
Affects gravity and terminal velocity
e.com/watch?v=ur40 O6nQHsw

5. Friction What is it: a force that opposes motion
Sliding: Involves 2 objects, 1 that slides past another
A box will experience less friction on a smooth surface than on a rough surface
Rolling: Involves 2 objects, 1 of which has rolls
Billiards
Fluid: Involves 2 objects; 1 of which is a fluid
Car engines
Static: 2 objects which are not moving in relation to each other
Tire touching the ground