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
Explanation (300 words):
Weightlessness, often called “free fall,” occurs when there is no support force acting on your body—essentially when you are falling under the influence of gravity alone. Among the choices given, falling from a roof is the only situation where this condition is truly met.
Let’s break it down:
- While accelerating downward in an elevator: You may feel lighter if the elevator is accelerating downward, but unless it’s in free fall (cable snapped, for instance), you are still being supported by the floor. So you are not truly weightless—just experiencing reduced weight.
- While falling from a roof: This is the correct answer. When you fall from a roof, you and everything on you accelerate downward at the same rate due to gravity. There is no normal force pushing up from beneath you (like a floor or ground), and thus, you feel no weight—this is true weightlessness. It’s the same sensation astronauts experience in orbit, even though gravity is still acting on them.
- While walking on the Moon: Although gravity is weaker on the Moon (about 1/6th of Earth’s gravity), it still exists. You feel lighter because of reduced gravity, but not weightless. Your body still presses against the lunar surface and feels a normal force pushing up, so you still experience weight, albeit less.
- While parachuting from an airplane: Once your parachute opens, you reach terminal velocity—a constant speed due to the balance between gravity pulling you down and air resistance pushing you up. You are no longer in free fall, and you can feel your own weight due to the resistance acting on your body.
In summary, true weightlessness occurs only when you are in free fall, like falling from a roof, where gravity is the only force acting on you.
