John walks along a green path of 2500m from the Start to the End in 50 minutes.
What is Velocity?
is the rate of change of displacement.
- A vector quantity (i.e. has both magnitude and direction)
- SI unit: metre per second (m s⁻¹)
- The displacement travelled by john is the shortest distance from sthe start to the end which is 500m.
What is the velocity of John?
Speed=500/3000
=0.17m s⁻¹ (2dp)
John is travelling at at velocity of 0.17m s⁻¹
Note: Always convert the time to seconds first.
Classic Velocity Questions
1a. A car travels around a circular track at a constant speed of 40 km/h. Explain why the car’s velocity is not constant.
- Velocity is a vector quantity that depends on both direction and magnitude.
- Since the car’s direction changes continuously as it travels around a circular track, its velocity changes all the time.
1b. Is the car accelerating? Explain your answer.
- Acceleration is defined as the rate of change of velocity with time.
- Since velocity is changing, the car is accelerating.