Question

1    My mass is about 75 kg. When I climb my stairs, I rise vertically by 3 metres.

a    What is my weight (in newtons)?

b   How much gravitational potential energy do I gain?

Answer 1

a. The weight is

$$W=mg=75·9.8=735\text{ N}.$$

b. The increase in potential energy is

$$E=Wh=735·3=2205\text{ J}.$$