# Velocity of a ball (kg) droped from height (m)

1. Feb 15, 2012

### Pippa9

1. The problem statement, all variables and given/known data

A ball of mass 0.5kg is dropped from a height of 5m what is the greatest velocity it will have just before hitting the ground?

2. Relevant equations

f=m*g
a= change in velocity/change in time

3. The attempt at a solution
m=.5kg
h=5m
a=9.8m/s

f=m*g
f= .5*9.8= 4.9N

I don't know what other equations to use to find velocity

2. Feb 15, 2012

### xlava

You can solve this one of two ways:

Energy approach: Energy at highest point is equal to the kinetic energy at the lowest point, since all potential energy is converted to kinetic as the ball is about to hit the ground.

Kinematics approach: Use the time independent kinematics equation.

Post if you need more specific guidance, because this is a relatively simple problem.

3. Feb 15, 2012

### Shootertrex

You can also use these equations together to solve:
$d=0.5at$2$+v_{i}t+d_{i}$
$a=\frac{Δv}{Δt}$.

Last edited: Feb 15, 2012