**Speed- is the distance an object travels divided by the time the object was travelling. It is a
scaler quantity which means that there is no direction , therefore in other words it is the magnitude of velocity. **

**Mass- the quantity of matter an object contains. The mass of an object is
not dependent on gravity and therefore is different from but proportional to its weight.**

**Acceleration- The rate of change of velocity with respect to time. **

**Force of Gravity- the force of attraction between masses, the gravitational force has an infinate
range. **

**Force- The capacity to do work or cause physical change. **

**Momentum- the product of an object's mass and its velocity.**

**Impulse- the product of the force exerted on an object and the time interval over which the force
acts. **

**Law of action-reaction- ** **this law states that for every applied action force
there is an equal and opposite reaction force.**