Q1. A wrecking ball (weight = 4600 N) is supported by a boom, which might be assumed to be uniform and has a weight of 3600N. As the drawing shows, a support cable runs from the top of the boom to the tractor. The angle between the support cable and the horizontal is 32°, and the angle between the boom and the horizontal is 48°.

Q2. The Stardust spacecraft was designed to visit a comet and bring samples of its material back to the earth. The craft is 1.70 {rm m} across and has a mass of 385 {rm kg}. In January 2004, from the distance of 237 {rm km}, it took the photograph of the nucleus of comet Wild2. The distance across this nucleus is 5.0 {rm km}, and we can model it as an approximate sphere. Since astronomers think that comets have a composition alike to that of Pluto, we can assume a density the same as Pluto's, which is 2.1 {rm g/cm^3}. The samples taken will be returned to earth on Jan. 15, 2006.

What gravitational force did the comet exert on the spacecraft when it took the ?
Answer is F =6.29×10-5 {rm N} 

evaluate this force with the force that the earth's gravity exerted on it when the spacecraft was on the launch pad?

A. F>mg
B. Fapprox mg 
C. F