Tony pulls a luggage cart at an angle of 30° to the horizontal. The luggage cart has a mass of 35 kg, and he pulls with a force of 75 N. a. What is the normal force on the luggage cart?
b. What force would Tony need to apply at a 30° angle to pull the luggage cart completely off the ground?
c. How does your answer in part (b) change as the angle increases?

chemical energy --> gravitational potential energy --> kinetic energy --> elastic potential energy --> gravitational potential energy

explanation:

when emma starts the hike, the chemical energy stored in her body is used to climb up the mountain, and so she gains gravitational potential energy (because at the end, she will be at a higher height h above the ground). then she goes bungee jumping: as she falls, this gravitational potential energy is converted into kinetic energy (because her speed increases as she falls down), until the point when the rope stretches, and she stops moving. at that moment, all the kinetic energy is converted into elastic potential energy due to the stretching of the rope. then, this energy is released because the rope returns to its natural length, and emma gains a small increase in altitude , so she gains some gravitational potential energy.