Newton's Theory of gravity help please..? need in 3 hours please help?

Question

I'm stuck on the last 3 questions.... please help me thanks..do any question u know


1. Two 100 kg lead spheres are suspended from 100m long massless cables. The tops of the cables have been carefully anchored exactly 1m apart. What is the distance between the centers of the spheres.

2. A 1.0kg object is released from rest 500km ( approx. 300 miles) above the earth.
a.What is its impact speed as it hits the ground? Ignore air resistance.
b. What would the impact speed be if the earth were flat?
c. By what % is the flat-earth calculation in error.
d. Suppose a space shuttle astronaut, while out for a stroll, "drops" a 1.0kg hammer. Will it fall to earth? Explain why or why not.

3. 2 identical planets of mass M and radius R spaced 6R apart. Ignore the rotation of the planets about each other .What is the escape speed of a rocketlaunched from (a) point A(first planet) and (b) point B(the middle point between first planet and second?

Answer 1

1.
There are 2 forces:
The earth's gravitational pull with g=9.81m/s°2
and the attraction between the 2 masses with G=6.67 .....

I can't write all these formulas but the solution is:

x=G/g * 100m/1m°2 * 100Kg
x=6.8*10°-5 m

the distance between the centers of the spheres = 1m-2x

Answer 2

Any body suspended in space will remain in space until made aware of its situation.

I'm sorry I suck at physics.

But I will star your question, so some of my contacts which are good at it will answer.