Marshmallow Launcher lab Draw a free body diagram for the marshmallow

a) Sitting on the device just before launch
b) At the maximum height
c) When it comes to rest

I got part a, I need help with b and c.

Suppose that three astronomical objects, 1, 2, and 3 are observed to lie on a line, and the distance from object 1 to object 3 is d. object 1 has four times the mass of object 3, and seven times the mass of object 2. find the distance between objects 1 and 2 for which the net force on object 2 is zero.