Vertical motion SUVAT equations

Hi everyone,
I've been struggling with these Maths questions and was hoping someone could help me out.

1. A golf ball is thrown vertically upwards from the ground with a velocity of 42m/s. How long is the golf ball more than 87.5m above the ground?

2. A ball is projected vertically upwards from an 11.4m high balcony. It takes the ball T seconds to reach its maximum height and 4.3 seconds to land on the ground. Find the value of T.

Any help is appreciated!

Reply 1

MindMax2000

Universities Forum Helper

Original post by username6583999

The main SUVAT equations are:
v^2 = u^2 + 2as
v = u + at
s = ut + (1/2)at^2

1. A golf ball is thrown vertically upwards from the ground with a velocity of 42m/s. How long until(?) the golf ball is(?) more than 87.5m above the ground?
Not sure if I agree with the grammar in the question.
Try using s = ut + (1/2)at^2

2. A ball is projected vertically upwards from an 11.4m high balcony. It takes the ball T seconds to reach its maximum height and 4.3 seconds to land on the ground. Find the value of T.
When you are trying to find max vertical height, my go to equation is v^2 = u^2 + 2as (partly because I am a little lazy).
Instead, look at s = ut + (1/2)at^2 to find the time. Since the ball is catapulted (because projected is such a generic term) from a height of 11.4m above the ground, you will need to set s = -11.4 to find the time. Once you have found u, consider using v = u +at to find what you need.