# Motion of a ball down a cliff

1. Sep 16, 2007

### luna02525

1. The problem statement, all variables and given/known data

You are standing at the top of the cliff that has a stairstep configuration. There is a vertical drop of 6m at your feet, then a horizontal shelf of 10 m, then another drop of 4m to the bottom of the canyon, which has a horizontal floor. You kick a .93 kg rock, giving it an initial horizontal velocity that barely clears the shelf below. The acceleration of gravity is 9.8 m/s^2. Consider air friction to be negligible. What initial horizontal velocity $$v$$ will be required to barely clear the edge of the self below you.

Edit: Solution found.

Last edited: Sep 16, 2007
2. Sep 16, 2007

### Staff: Mentor

We request students show some work and write the appropriate equations.

The problem reqires an object to clear a point 6 m below and 10 m horizontally displaced, and one has to determine the horizontal velocity to achieve the trajectory to accomplish this.

What is the initial vertical velocity? What are the equations of motion in the horizontal and vertical?

See - http://hyperphysics.phy-astr.gsu.edu/hbase/traj.html#tra11 (horizontal launches)

3. Sep 16, 2007

### ThomasHW

I saw this exact question somewhere else, I believe on this forum. I just can't find it.

4. Sep 16, 2007

### luna02525

I actually determined a solution for this problem (see edit) but thank you! I did have equations shown and attempted work but incidentally, I erased it all when I found a solution. It took me a while to find it but I'm slowly beginning to understand.