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:
Correct Answer: While falling from a roof
The sensation of weightlessness occurs when there is no normal force acting on your body. This usually happens when you are in free fall, meaning the only force acting on you is gravity, and there’s no support force (like from the ground or a chair) pushing back up.
Among the given options, falling from a roof is the only situation where you are in true free fall. In this case, you are accelerating downward at the same rate as gravity (approximately 9.8 m/s²), and nothing is pushing up against your body to create the feeling of weight. Your body and all objects around you fall at the same rate, making it feel as if there is no gravity—hence, you feel weightless.
Let’s look at the other options:
- While accelerating downward in an elevator: You may feel lighter if the elevator accelerates downward, but unless the acceleration equals gravity, you’re not in free fall. A support force from the floor still exists, so you do not feel completely weightless.
- While walking on the Moon: The Moon has gravity (about 1/6th that of Earth), so you would still have weight, just much less than on Earth. You feel lighter but not weightless. There’s still a surface pushing up on your feet.
- While parachuting from an airplane: After the parachute opens, you are no longer in free fall. Air resistance balances much of your weight, and you feel a support force from your harness. Even before the parachute opens, air resistance builds up, so true weightlessness is brief and not sustained.
Therefore, falling freely from a roof is the best example where you would feel truly weightless, due to the absence of any support or contact force acting against gravity.
