Vertical Motion under
Gravitational
Acceleration
The following formulae can be used to
calculate velocities and accelerations:
𝑣 = 𝑢 ± 𝑔𝑡
2
𝑣
=
2
𝑢
± 2 𝑔𝑠
𝑠 = ut ±
1
2
𝑔𝑡
2
However in this course we will mainly
use the First Principle Formulae
g=
𝑣−𝑢
𝑡
𝑣=
𝑢+𝑣
2
𝑣=
𝑠
𝑡
A ball is thrown straight upward with a velocity of 30 m/s and
reaches its maximum height after 3.058 seconds.
Calculate the time it takes for the ball to reach the ground from its maximum
height.
Calculate the velocity of the ball before it hits the ground again.
Therefore things to note:
The velocity of an object at maximum height is equal to zero
(
V = 0, @max height)
The time that an object takes to reach its maximum height is equal to the time it takes to drop
back to the ground
t t
( up = down)
The velocity at which an object was thrown upward is equal to the velocity of the object before
it hits the ground.
(
Uup = Vdown)