Acceleration is the rate of change of velocity. It is the amount that velocity changes per unit time.
If an object accelerates from an initial velocity (u) up to a final velocity (v) then the average acceleration of an object can be calculated using the equation:
This is when:
If an object is slowing down, it is decelerating (and its acceleration has a negative value).
A car takes 8.0 s to accelerate from rest to 28 m/s. Calculate the average acceleration of the car.
final velocity, v = 28 m/s
initial velocity, u = 0 m/s (because it was at rest – not moving)
change in velocity, v - u = (28 - 0) = 28 m/s
A car takes 25 s to accelerate from 20 m/s to 30 m/s. Calculate the acceleration of the car.
final velocity, v = 30 m/s
initial velocity, u = 20 m/s
change in velocity, v - u = (30 - 20) = 10 m/s
Some typical values for acceleration in metres per second (m/s2) include:
|Method of travel||Typical acceleration (m/s²)|
|Rollercoaster||30 - 60|
|Formula One car||49|
The acceleration in freefall due to the Earth's gravity is 10 m/s2.
g = 10 m/s2