# Direction of a thrown ball

1. Apr 15, 2007

### grando69

1. The problem statement, all variables and given/known data
A child throws a ball with a speed 20ms-1 from a window 5m above horizontal ground. If the ball hits the ground 1.5 seconds later, find the direction of the projection.

2. Relevant equations
The basic equations of motion:
s=ut+1/2at^2
v=u+at
v^2=u^2+2as

3. The attempt at a solution

2. Apr 15, 2007

### hage567

What have you tried? Show your thoughts.

3. Apr 15, 2007

try breaking the speed of the ball into component form, so that you have a horizontal and a vertical component. assuming that there is no air resistance, the horizontal component will remain constant as there is no acceleration occurring in the horizontal plane. The only acceleration present is gravity which acts downwards in the vertical plane.
the horizontal component will be: $$ut\cos \theta$$
the vertical component will be: $$ut\sin \theta - \frac{{gt^2 }}{2}$$