1. The problem statement, all variables and given/known data 1. If the mass of a satellite is doubled, the radius of its orbit can remain constant if the speed of the satellite: a. increases by a factor of 8 b. increases by a factor of 2 c. does not change d. is reduced by a factor of 8 e. is reduced by a factor of 2 2. Astronauts orbiting in a satellite 300km above the surface of the earth feel weightless. Why ? Is the force of gravity exerted by the earth on them negligible at this height ? 3. Five equal masses M are equally spaced on the arc of a semicircle of radius R. m is located at the center of curvature of the arc. (a) If M is 3kg,m is 2kg, and R is 10cm, what is the force on m due to the 5 masses. If m is removed, what is the gravitational field at the center of curvature of the arc ? 2. Relevant equations F= -Gm1m2/ r^2, T^2= 4pi^2r^3/GM(s) 3. The attempt at a solution 1. I chose e but I am wrong. What would be the appropriate way to find out the answer of this question ?? 2. I said that the distance r^2 is really big so F is negligible at this height. I am wrong again. How should I explain this ?? 3. So I did this problem wrong. Is it true that 4 of M are canceled because they are opposite ? So the only mass that affect is M which is right above m right ?