# Need help with force/tension problems

1. Oct 13, 2004

### theresa d

if anyone could give any tips, advice, help, formulas etc., on the solving these problems, i woudl be eternally grateful.

at what distance from the earth will a spacecraft traveling directly from the earth to the moon experience zero net force because the earth and moon pull with equal and opposite forces?

Figaro the cat (5.0 kg) is hanging on the tablecloth, pulling Cleo's fishbowl (11 kg) toward the edge of the table. The coefficeint of kinetic friction between the tablecloth (ignore its mass) under the fishbowl and the table is 0.44. (a) what is the acceleration of Figaro and the fishbowl? (b) if the fishbowl is 0.90m from the edge of the table, how much time does it take for Figaro to pull Cleo off the table?

these are from the Giancoli physics book by the way, if that helps at all...

2. Oct 14, 2004

### aekanshchumber

1. Let the mass of the Earth be Me and moon is Mm, distance from earth is De and from moon is Dm, let the mass of the rocket be M,
Both force are in equilibrium,
(G*M*Me)/(De)^2 = (G*M*Mm)/(Dm)^2
Me/(De)^2 = M*Mm/(Dm)^2
Me/Mm = (De/Dm)^2
Substitute the value or calculate the ratio from it.

3. Dec 4, 2007