Newton's Thrid Law Question

1. Mar 16, 2010

Paymemoney

1. The problem statement, all variables and given/known data
I have a mass of 65kg. If I jump off a 120-cm-high table, how far toward me does Earth move during the time i fall?

2. Relevant equations
F=ma

3. The attempt at a solution

P.S

2. Mar 16, 2010

kuruman

What is the force that you exert on the Earth? Knowing this force, can you calculate the Earth's acceleration?

3. Mar 23, 2010

Paymemoney

ok, i had another try of this question and i went W=mg which is 68 * 9.8 i get the force 666.4N then what should i do next?

4. Mar 23, 2010

kuruman

If 666.4 N is the force that the Earth exerts on you, what the force that you exert on the Earth?

5. Mar 30, 2010

Paymemoney

the same because of Newton's Third Law, so i found the acceleration by doing the following:
Mass of Earth is 5.97 * 10^24 (according to the book)

637 = (5.97 *10^24)a
a=1.06*10^-22 m/s^2

now how do i find how far toward me does Earth move during the time i fall?

6. Mar 30, 2010

kuruman

How many seconds does it take you to fall 1.20 m to the surface of the Earth with an acceleration of 9.8 m/s2? In that same amount of time the Earth "falls" towards you with an acceleration of 1.06x10-22 m/s2. Use the kinematic equation to find the distance.

7. Mar 30, 2010

Paymemoney

thanks i know how to do it now.