1.) calculate the weight of a 7kg object
2.) calculate the mass of a 65 n object)

Explanation:

Mass and Weight

The mass m of an object is known as the amount of material it has. Weight is the force that mass is attracted to planet Earth or another object much bigger than it. The relation between them is

Where g is the acceleration of gravity ( on Earth)

1. If we know the mass of an object m=7 kg, we can compute its weight

2. If we know the weight W=65 N of some object, we can compute its mass

i'm thinking more like energy

moving ball hits still ball. mover stops, hit ball moves. momentum transfer.