Hmm…what are
they talking
about!!?
What IS
acceleration?!!!!
What is acceleration?
The acceleration of an object is it’s change in
velocity over time. It occurs due to a force being
applied. Acceleration can also result in a change
in direction.
To calculate acceleration:
𝑐ℎ𝑎𝑛𝑔𝑒 𝑖𝑛 𝑣𝑒𝑙𝑜𝑐𝑖𝑡𝑦
𝑎𝑐𝑐𝑒𝑙𝑒𝑟𝑎𝑡𝑖𝑜𝑛 =
𝑡𝑖𝑚𝑒
𝑐ℎ𝑎𝑛𝑔𝑒 𝑖𝑛 𝑣𝑒𝑙𝑜𝑐𝑖𝑡𝑦 = 𝑓𝑖𝑛𝑎𝑙 𝑣𝑒𝑙𝑜𝑐𝑖𝑡𝑦 − 𝑠𝑡𝑎𝑟𝑡𝑖𝑛𝑔 𝑣𝑒𝑙𝑜𝑐𝑖𝑡𝑦
∴ 𝑎𝑐𝑐𝑒𝑙𝑒𝑟𝑎𝑡𝑖𝑜𝑛 =
𝑓𝑖𝑛𝑎𝑙 𝑣𝑒𝑙𝑜𝑐𝑖𝑡𝑦 −𝑠𝑡𝑎𝑟𝑡𝑖𝑛𝑔 𝑣𝑒𝑙𝑜𝑐𝑖𝑡𝑦
𝑡𝑖𝑚𝑒
Acceleration
Velocity is measured in metres per second (m/s)
Time is measured in seconds (s)
The standard unit for acceleration is metres per second, per
second (yes, it’s supposed to be repeated). This is written as m/s2.
(It can also be written as m.s-2 )
Acceleration Problems
1. A cyclist accelerates from 0 m/s to 30 m/s in 8 seconds. What is
his acceleration ?
Final velocity = 30m/s
Starting velocity = 0 m/s
Time = 8s
𝑓𝑖𝑛𝑎𝑙 𝑣𝑒𝑙𝑜𝑐𝑖𝑡𝑦 − 𝑠𝑡𝑎𝑟𝑡𝑖𝑛𝑔 𝑣𝑒𝑙𝑜𝑐𝑖𝑡𝑦
𝑎𝑐𝑐𝑒𝑙𝑒𝑟𝑎𝑡𝑖𝑜𝑛 =
𝑡𝑖𝑚𝑒
30 − 0 30
𝑎𝑐𝑐𝑒𝑙𝑒𝑟𝑎𝑡𝑖𝑜𝑛 =
=
8
8
𝑎𝑐𝑐𝑒𝑙𝑒𝑟𝑎𝑡𝑖𝑜𝑛 = 3.75𝑚/𝑠 2
Acceleration Problem
2. A ball is dropped from the top of a building. After 2 seconds,
it’s velocity is measured to be 19.6 m/s. Calculate the
acceleration for the dropped ball. (note: the ball’s initial velocity
is 0m/s).
Final velocity = 19.6m/s
Starting velocity = 0 m/s
Time = 2s
𝑎𝑐𝑐𝑒𝑙𝑒𝑟𝑎𝑡𝑖𝑜𝑛 =
𝑓𝑖𝑛𝑎𝑙 𝑣𝑒𝑙𝑜𝑐𝑖𝑡𝑦 −𝑠𝑡𝑎𝑟𝑡𝑖𝑛𝑔 𝑣𝑒𝑙𝑜𝑐𝑖𝑡𝑦
𝑡𝑖𝑚𝑒
19.6 − 0 19.6
𝑎𝑐𝑐𝑒𝑙𝑒𝑟𝑎𝑡𝑖𝑜𝑛 =
=
2
2
𝑎𝑐𝑐𝑒𝑙𝑒𝑟𝑎𝑡𝑖𝑜𝑛 = 9.8𝑚/𝑠 2
HOORAY! I now
understand what
acceleration is.