# Question #04fd1

##### 2 Answers

The ball will reach a max height of

#### Explanation:

We use the kinematic equation connecting various quantities of interest. The maximum height is reached when upwards velocity is

1. To calculate Max height

Final velocity

Inserting given values we get, remember, direction of acceleration due to gravity is opposite to the direction of initial velocity

2. To calculate time taken to reach maximum height we use the other kinematic equation

Inserting given values we get

h= 45 m; t = 3 s

#### Explanation:

The initial Kinetic energy (where potential energy is zero) becomes only potential energy (where the ball reaches the max height and its speed is zero).

but, since the mass is the same

and

from the second law of motion

now let's verify in the first law of motion

45 = 45 m