Find the force of Gravity (newtons) and the weight (newtons) of each object...

1. Find the force of Gravity (newtons) and the weight (newtons) of each object:

a)An object with a mass of 65 kg?

b)An object with a mass of 45kg

c)An object with a mass of 56kg

2. An object has a force of gravity of -780N, what is its mass?

Please indicate which equation you use, what variable corresponds to each number, and how you got the number that goes with the variable.

Thanks!

1)

a) F= ma Force = Weight, Aceleration = Gravity
W= 65kg * -9.8m/s^2 = -637 N
b)
W= 45kg * -9.8m/s^2 = -441 N
c)
W= 56kg * -9.8m/s^2 = -548.8 N

2) W= mg
m = w/g
m = -780n/-9.8m/s^2 = 75.59kg

Sorry, I have my own homework to do :p