In which of the following cases would you feel weightless?
- while accelerating downward in an elevator
- while falling from a roof
- while walking on the Moon
- while parachuting from an airplane
The Correct Answer and Explanation is:
The correct answer is: while falling from a roof.
Explanation
The sensation of weightlessness occurs when there is no normal force acting on your body. In most everyday situations, you feel your weight because the ground or a surface (like a chair or floor) pushes up against your body with a force equal to gravity. However, when you are in free fall — falling solely under the influence of gravity with no resistance or support — that opposing force disappears, and you feel weightless.
Let’s examine the given options:
- While accelerating downward in an elevator – You might feel lighter if the elevator is accelerating downward, but not weightless unless the cable completely breaks and you’re in free fall. In that extreme case, you would feel weightless, but in typical downward acceleration, you still feel some force from the floor of the elevator.
- While falling from a roof – This is the correct choice. As you fall, gravity is the only force acting on your body (ignoring air resistance), and there is no surface pushing back against you. Since there’s no normal force, you feel weightless. This is true “free fall” — your body is accelerating downward at the same rate as gravity, making you feel as if you’re floating.
- While walking on the Moon – Although gravity is weaker on the Moon (about 1/6th of Earth’s), it still exists. You have weight and you feel it, albeit less than on Earth. You do not feel weightless.
- While parachuting from an airplane – Once the parachute opens, air resistance balances much of the gravitational force, and you reach terminal velocity. The air pushing up on you gives you a sense of support, so you no longer feel weightless.
In conclusion, you feel truly weightless only when in free fall — such as while falling from a roof — because there’s no contact force to give your body the sensation of weight
