Motion/Mass and Weight/Density

Speed

Distance travelled per unit time (Speed = Distance/Time)

Velocity

Speed in a given direction

Speed and Distance Time Graph

Distance Time Graph

Slope = Speed

Speed Time Graph

• Slope = Acceleration

• Area under the graph = Distance

Acceleration of free fall near the surface of the earth

9.8m/s²

Acceleration

Change in velocity per unit time (velocity/time)

Motion of Objects falling

When a object falls through the sky in vaccum its acceleration is 9.8m/s as the only force is weight, when it falls in air, air molecules act on it creating a upward frictional force. As speed increases air resistance also increases. Eventually there is no resultant force and no acceleration and the object moves at a constant maximum speed known as terminal velocity

Mass

Measure of quanity in a object

Weight

Gravitational force acting on a object with mass

Gravitational Field Strength

Force per unit mass (g=W/M) = acceleration of free fall

Density

Mass per unit volume

Which Floats

Object with lower density