Study of motion _______________________________________________________________________________________________________________________________________________________________________________________________________________________
15. Acceleration
From rest, a rally car can reach a velocity of 100 km/h in 2,5 s or less. It gains velocity very rapidly. It has a high acceleration.
Like velocity, acceleration has a direction, it is a vector quantity.
Acceleration is calculated as follows:
Figure 8.8
An object is said to be accelerating if it is :
- Speeding up - Slowing down - Changing direction - Speeding up and changing direction - Slowing down and changing direction
Acceleration can be positive or negative. If a car has an acceleration of -4 m/s2, it is losing 4 m/s of speed every second. A negative acceleration is sometimes called deceleration.