# How do you find how far an object will go?

1. Sep 23, 2011

### angiep410

A projectile is shot from the edge of a cliff 172.0 m above the ground level with an initial speed of 66.00 m/s at an angle of 68.00 ° with the horizontal.
What is the range X of the projectile as measured from the base of the cliff?

I would normally use a range equation, but I didn't think that would work here since the object is not coming back to the starting height.

2. Sep 23, 2011

### sandy.bridge

For this, you can calculate the time required to reach its maximum height in the projectile. Moreover, after you have done this, you can calculate the time required to reach its minimum point from its maximum. Adding these two times will give you the time for the entire route. You can then apply this time in the horiztonal direction as its velocity.

3. Sep 23, 2011

### angiep410

the time it takes for the object to hit the ground is 14.8 seconds and the maximum height is 191 m. Now what do I do?

4. Sep 23, 2011

### Staff: Mentor

How did you calculate those numbers? What equations did you use? If you show us your work, it would be easier to help you.

5. Sep 23, 2011

### angiep410

they were given to me

6. Sep 23, 2011

### Staff: Mentor

Part of the Homework Help Template that you were provided when you started this thread (and you deleted) asks for the Relevant Equations. What are the Relevant Equations for motion under the influence of a constant acceleration (gravity)?

And what is the equation for the vertical motion of a projectile as a function of Vo, Yo, a, and time? How would you apply that equation to this question? And use the hints you were given in Post #2...