| acceleration | The rate of change in velocity. Acceleration is an increase in speed. Equation=Final Velocity -Original Velocity divided by time. |
| gravity | The force of attraction that depends on the mass of 2 objects and the distance between them; responsible for accelerating an object toward the Earth. |
| potential energy | The energy of shape or position; stored energy |
| kinetic energy | The energy that a moving object has to its motion;energy of motion |
| force | A push or pull that gives energy to an object sometimes causing a change in the motion of the object. |
| friction | A force that acts in the opposite direction of motion; will cause an object to slow down and finally stop. |
| weight | The measure of the force of attraction between objects due to gravity. Equation=Mass times Acceleration due to gravity |
| decelerate | If there is a decrease in velocity, the value of acceleration is negative. Negative acceleration is deceleration. When you slow down, you decelerate. |