### Escape from Planet Earth

How fast would you have to throw a ball upwards so that it would never land?

### Gravity Paths

Where will the spaceman go when he falls through these strange planetary systems?

# Receding Baseball

##### Stage: 5 Challenge Level:

Suppose a pitcher throws a ball in such a way that the distance between him and the ball is always increasing. It is given that the acceleration due to gravity is $g = 9.81 \mathrm{m/s}^2$ and any air resistance is negligible.

First of all, draw an example throw which has this property, and draw another which doesn't. Find conditions which are necessary to make such a throw.

1) Does it depend on the angle at which the ball is thrown?

2) Does it depend on the initial speed of the ball?

3) How does your result change if the player is at different altitudes?