# 8 | Summary

## Summary

• A scalar quantity has a magnitude but no direction.
• Examples of scalar quantities include distance, speed, time, power and energy.
• A vector quantity has a magnitude and a direction.
• Examples of vector quantities include displacement, velocity, acceleration, force and momentum.
• Distance is a measurement of the actual path travelled by an object.
• Displacement is a measurement of how far away an object is from its original position.
• Speed is a measure of how fast something moves.
• It is measured in units such as metres per second (m/s) and kilometres per hour (km/hr).
• Average speed is an overall measurement of speed between two points in time.
• Instantaneous speed is a measure of speed at a particular point in time.
• Average speed can be calculated using the formula:
• • Speed can be converted from m/s to km/hr by multiplying by 3.6.
• Speed can be converted from km/hr to m/s by dividing by 3.6.
• Distance travelled can be calculated using the formula:
• • Time taken can be calculated using the formula:
• • Velocity is a measure of the rate at which displacement changes.
• It can be calculated using the formula:
•  (Image: PhotoMIX-Company, Pixabay)