Question

Two isolated masses, M1 = 2.20 kg and M2 = 589 kg are initially rest, a distance d= 161 cm apart. Their gravitational attraction is the only force acting. Calculate the time it takes for M1 to move from that distance to 159 cm from M2. Assume that M2 does not move and that the force is constant over that small distance, and equal to that at 160 cm.

Answer 1

This is just the same as figuring the time it takes for an object to fall 2cm on earth, except that the gravitation acceleration is not 9.81 m/s^2, but

GM/r^2

where you have the values for G,M and r. Once you have that evaluated,

s = 1/2 at^2

and you can just plug in s=0.02m and a is the acceleration figured above.

Answer 2

what would I use for r and M?

Answer 3

will G be 6.67*10^(-11)

Answer 4

Yes, but be sure to use distances in meters not cm (1.61 meters apart)