# Range and Elevation Equations

1. Sep 8, 2009

### r_swayze

I have no idea where to begin with this problem. To me it seems like its missing information.

You desperately want to qualify for the Olympics in the long jump, so you decide to hold the qualifying event on the moon of your choice. You need to jump 7.52 m to qualify. The maximum speed at which you can run at any location is 5.90 m/s. What is the magnitude of the maximum rate of freefall acceleration the moon can have for you to achieve your dream?

any help?

2. Sep 8, 2009

### rl.bhat

Problem is based on the projectile motion. Can you state the relevant equations?
Here the range and the initial velocity is given.
What should the the angle projection for maximum range?

3. Sep 8, 2009

### r_swayze

according to the book the relevant equation is:

change in x = (-v^2 sin(2*theta)) / ay

I dont know theta so I dont think I can use this equation right?

and isnt 5.90 m/s the velocity of the x component? or is that the initial velocity of the jump?

4. Sep 8, 2009

### Phrak

That's correct. Without calculus you can't calculate what trajectory will give you the greatest distance. On the other hand, maybe you were told it was 45 degrees.

5. Sep 8, 2009

### rl.bhat

The velocity is the initial velocity of jump. For maximum range, sin2θ should be 1 or θ should be 45 degrees.

6. Sep 8, 2009

### Phrak

How is theta defined in that equation?

7. Sep 9, 2009

### rl.bhat

The angle through which the long jumper leaves the ground. But you have to assume him as a point object.