# Projectile motion involving mass

1. Mar 10, 2014

### Glype11

If the only variable that is changed is mass. What equation would I use to find the distance an object travels that is shot horizontally at a velocity (v) and I would like to be able to calculate the change in velocity?

2. Mar 10, 2014

### Staff: Mentor

What is the mechanism by which the mass changes? It makes a big difference exactly how this happens.

3. Mar 11, 2014

### mic*

If "an object travels that is shot horizontally at a velocity (v)", any object shot at velocity (v) will travel the same horizontal distance (neglecting air resistance). The horizontal component of travel experiences no acceleration so the initial velocity (v) remains constant.
The vertical component is experiencing a downward acceleration due to gravity. This acceleration is the same for any mass object so they reach the ground together. Like dropping a basketball and a medicine ball at the same time - they reach the ground together.
If the mechanism that shoots the first object remains the same, then shoots a larger mass object, this second object will not have "velocity (v)" to begin with. Is this what you mean?

4. Mar 11, 2014

### Glype11

The case I had in mind, was comparing two projectiles fired at the same velocity, the heavier one will travel farther.
I know it comes down to aerodynamics. I wanted to see if there was a more simplified way of solving these types of problems rather starting with the drag equation.

5. Mar 11, 2014

### dauto

If you want to include the drag than there is no simple answer. Two objects with the same mass but different shapes will behave differently.