# Projectiles questions-Rush!

5
Projectiles- Physics11.
This is part of my lab, and i really can't figure this out:uhh:
So I need some help .,

Here are the questions ::

*Assume you can throw a baseball 40 meters on the earth's surface.How far could you throw that same ball on the surface of the moon, where the acceleration of gravity is one-sixth what it is at the surface of the earth??

*AND will the acceleration due to gravity be different at 1000 meters above the surface of the Earth?

Thank you sooo much..

Last edited: Nov 1, 2005
2. ### Pengwuino

7,118
Well for the first part, you can use the kinematic equations to determine how fast you actually threw the ball and plug this velocity into a new kinematic equation with hte moon's gravity in place of the earth.

5
Kinematics Equations?

Which question should i use?
Would i consider Initial Velocity at 0m/s
or the Final Velocity at 0m/s?
If the case is when you throw the ball ?
Thank you

5
Which question should i use?
Would i consider Initial Velocity at 0m/s
or the Final Velocity at 0m/s?
If the case is when you throw the ball ?
Thank you

5. ### Pengwuino

7,118
The initial velocity at 0m/s? You mean x=0. Use x=0 i suppose because on a level surface with no friction, it will have the same speed at the end and at the beginning. You do this for the case when the ball is thrown on earth.

6. ### verty

1,934
I don't see any other way to help than to show how I would approach this. Gravity only determines the time the ball remains in the air:

s = v_h*t
t = (v_v-u_v)/g

Go from here.

Last edited: Nov 2, 2005