# What is impact velocity?

1. May 21, 2006

### ohlhauc1

I am doing a dull vocabulary project, and I need to define impact velocity. I cannot find a suitable definition anywhere, although I have an idea. Does anyone have a good definition?

My thought is: Impact velocity is the maximum velocity obtained by an object before it is stopped by something and the velocity is 0.

Thanks

2. May 21, 2006

### Andrew Mason

It is the relative velocity of one mass to another an arbitrarily small time before the masses interact (by applying a force to each other). The impact need not reduce the velocity of the impacting object to 0. In fact, it rarely does.

For two objects, one of which is at rest, impact velocity would be defined as:

$$\vec v_{impact} = (m_1\vec v_{1f} + m_2\vec v_{2f})/m_1$$

where $\vec v_{1f} \text{ and} \vec v_{2f}$ are the velocities of the masses after the collision.

AM

Last edited: May 21, 2006