PE - Measurements Definitions and Equations

What is a scalar quantity?

A quantity that only has magnitude

What is a vector quantity?

A quantity that has both direction and magnitude

What is mass?

• The physical quantity of matter / substance in a body.

• Made of bone, muscle, tissue and fluid

• Measured in Kg

• Scalar quantity

What is weight?

• The force on a given mass due to gravity

• Measured in Newtons (N)

• To calculate weight

  • Weight = mass x gravity

  • Gravity being represented as 9.8

• Weight on the moon is 1/6th of the weight on earth

• Vector quantity

What is distance?

• Measured in meters

• The path the body takes as it moves from the starting to finishing position

• Scalar quantity

What is displacement?

• Measured in meters

• Shortest route in a straight line between start and finish position

• Vector quantity

What is speed?

• The rate of change of a position

• Calculated by

  • Speed = distance covered / time taken

• Scalar quantity

What is velocity?

• How fast the body travels in a certain direction.

• The rate of change of displacement

• Calculated by:

  • Velocity = displacement / time

• Vector quantity

What is acceleration?

• The rate of change of velocity

• When velocity increases, positive acceleration occurs

• When velocity decreases, negative acceleration occurs

• Calculated by:

  • Avg. acceleration = change in velocity / time

• Vector quantity

What is momentum?

• The product of the mass and velocity of an object

• Calculated by:

  • Momentum = mass x velocity

• Vector quantity