Number 10.3 . Please help me

(c) Calculate the time period if the hole were drilled through the Moon. 10.3. In Fig. 10.3, if there are a large number of forces acting on M, the result of combining them should be a single force and a torque. Why is there no torque? (Hint: Take an arbiu-ary point P and show that the forces pass through it.) 10.4. An object of mass m released at a very large distance from Earth falls toward Earth's center. Cal. culate the time it will take (a) to reach halfway to Earth's center. and (b) to reach from