An object in motion continues in motion with the same speed and in the same direction unless acted upon by an unbalanced force. Inertia = the resistance an object has, to a change its state of motion. 1st Law of Motion An object at rest will remain at rest unless acted on by an unbalanced or balanced force. Often called "the law of inertia".
Both balls will hit the ground at the same time Which ball will hit the ground first? ???
Gravity accelerates all objects at the same rate Acceleration is produced when a force acts on a mass. The greater the mass (of the object being accelerated) the greater the amount of force needed (to accelerate the object). 2ND Law of Motion The force of an object is equal to its mass times its acceleration .
For every action there is an equal and opposite reaction . " action " = action force " reaction " = reaction force . "equal" =equal in magnitude and "opposite" = opposite directions. 3RD Law of Motion Action-reaction force must occur in pairs!
FLICK KNIFE REASON : conservation of angular momentum
<ul><li>Momentum is the product of inertia and velocity . </li></ul><ul><li>Inertia means the tendency of something not to change </li></ul><ul><li>Velocity means how fast it moves. </li></ul><ul><li>So, momentum means the tendency of an object </li></ul><ul><li>in motion not to slow down. </li></ul>Angular momentum is the tendency of a rotating object to keep rotating at the same speed about the same axis of rotation.