A physics student stands in an 64th floor. The students weights 810 N.
What is his mass and normal force?
Mass is 83?
normal force is 810?
Normal force is indeed 810
mass = normal force /g
= 810/9.81
= 82.57 kg
but it depends what your class uses for g. I use 9.81 but some classes even use 10m/s^2
(I guess they live on a slightly more massive planet :)