# Calculating the Initial Velocity of a Ball Kicked at an Angle

## The Initial Velocity of a 500g Ball

A mass of 500g ball is kicked at angle of 45 degree to the horizontal. The ball reaches 12m height. To calculate the initial velocity of the ball, we can use the kinematic equation.

## Kinematic Equation

**Kinematic equations** are a set of equations used to describe the motion of objects, involving displacement, velocity, acceleration, and time. The equation for an object in motion with uniform acceleration is:

**v^2 = u^2 + 2as**

## Calculating Initial Velocity

To find the initial velocity of the ball, we rearrange the kinematic equation as follows:

**u^2 = v^2 - 2as**

Given:

**a = -9.8 m/s²** (negative due to deceleration/motion upward)

**s = 12m**

**v = 0 m/s** (final velocity is zero, ball stopped rising)

Calculating:

**u² = (0)² - 2(-9.8)(12)**

**u² = 235.2**

**u = sqrt(235.2)**

**u ≈ 15.33 m/s**

Therefore, the initial velocity of the ball is approximately **15.33 m/s**.

What is the kinematic equation used to calculate the initial velocity of the ball?

The kinematic equation used to calculate the initial velocity of a ball is: **u^2 = v^2 - 2as**