Consider applying Newton's second law to a man riding an elevator (perhaps to calculate his acceleration). Which of the following forces must be considered? Choose all that apply.
- The force that the man's feet exert on the floor of the elevator
- The force of gravity on the elevator
- The force the elevator cable exerts on the elevator car
- The force that the man's head exerts on his neck
- The force that the elevator floor exerts on the man's feet
- The force of gravity on the man