Displacement, velocity and speed

Question 1

Define position

Answer 1

• The vector separation of a point from a defined origin

Question 2

Define displacement

Answer 2

• A change of position

Question 3

Define velocity

Answer 3

• The rate of change of displacement
• V = dx/dt

Question 4

Define speed

Answer 4

• The magnitude of velocity

Question 5

Understand the difference between instantaneous and mean speed/velocity

Answer 5

• Instantaneous speed/velocity: This is at one instant in time, measured using a speed gun
• It is the gradient of the tangent of a distance/displacement-time graph
• Mean speed/velocity: This is the average speed/velocity over a time interval or over a fixed distance
• Average speed/distance = total distance travelled/displacement/total time taken