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:
Weightlessness occurs when a person experiences free fall, meaning they are accelerating downward at the same rate as the force of gravity, without any support or resistance. In this state, the feeling of weight is absent because the body is not in contact with any surface that exerts an upward force on it. This is referred to as “free fall” or “microgravity.”
Here’s why each option plays out the way it does:
- While accelerating downward in an elevator: If you’re in an elevator that is accelerating downward, you will feel lighter than usual due to a decrease in the normal force (the force the elevator floor exerts on you). However, this does not result in true weightlessness because you are still in contact with the elevator floor, and gravity is still acting on you. You may feel a reduction in weight but not complete weightlessness.
- While falling from a roof: When you fall from a roof, you are in free fall and experiencing a state of weightlessness. Your body is accelerating downward at the same rate as gravity, and there is no contact with any surface (unless you hit the ground). This is the textbook example of weightlessness, as you are effectively floating in free fall until you impact the ground.
- While walking on the Moon: On the Moon, gravity is only about 1/6th of Earth’s gravity. While you would feel significantly lighter compared to Earth, you would still experience a gravitational pull. Hence, you are not truly weightless because there is still a force acting on you (just much weaker than on Earth). You would feel the reduced weight but not complete weightlessness.
- While parachuting from an airplane: During parachute descent, you initially experience free fall, and at that point, you might feel weightless. However, as the parachute deploys and slows you down, you will feel a pull from the parachute, and you are no longer in free fall. Therefore, you’re not continuously weightless during the entire parachute ride.
In summary, while falling from a roof is the scenario where you are truly weightless due to free fall.
