# Force question

1. Jun 20, 2009

### cragar

how would we calculate the force if something was moving at a constant velocity
and hit a wall or the ground , i know that if the velocity was constant there is no force but if it hit a wall or something , would this just be a change in momentum p=mv

2. Jun 20, 2009

### Pengwuino

This is a common question. The net force exerted on an object is equal to $$\frac{{dp}}{{dt}}$$. You need to know the time interval that the force (ie the something changing velocity) acted upon in order to determine what hte force's magnitude was.

3. Jun 21, 2009

### granpa

Last edited: Jun 21, 2009