Acceleration. 10.3. Definition. The term acceleration describes all situations in which the speed is changing or acceleration (a) is the rate of change in speed. To solve this we examine the ratio of the change in speed ( Δ v) to the time interval ( Δ t) during which this change occurred.
If an object is travelling 4.5 m/s for a time of 1s, what is the objects acceleration?
After 2s? (assume uniform a)
After 3s? (assume uniform a)
When solving for acceleration use:
When solving for Δv (change in speed) use:
When solving for Δt (change in time) use:
v2 – v1
v2 and v1 are often times represented by vf (final speed) and vi (initial speed).
Solving for vf use:
vf = vi + aavΔt
Solving for vi use:
vi = vf – aavΔt
Solving for t use:
t = Vf - Vi
For example, when a car comes to a stop the v1 will be your speed when you apply the brakes and v2 will be zero. This (v2 – v1) will give you a negative acceleration