Static friction: The fiction acts on none moving objects. Rolling friction: If an object rolls across a surface Fluid Friction: When a solid is in motion because it moves through the fluid. (water, air, oil) Sliding Friction: Two surfaces that slide over each other
Projectile Motion & Elastic Forces
Elasticity is the ability of a material to return back to it's original shape after being squeezed or stretched.
Projectile is an object that is thrown.
Air resistance: Stacey went parachuting the push upwards is the air resistance and the pull downwards is gravity. Free Fall: Lydia threw the ball up into the air and since the only force acting upon it was gravity she knew the ball was in free fall.
Tension is an elastic force that stretches or pulls matter.
When matter is pushed or squeezed together, that is a type of elastic force called compression.