The apparent weight of a person standing in a lift accelerating upwards is
- A. greater than their true weight
- B. less than their true weight
- C. equal to their true weight
- D. zero
Explanation
The floor must both support the weight and supply the extra upward force to accelerate the person, so the normal reaction, which is what the scales read, is m times g plus a. Accelerating downwards makes the reading smaller, and in free fall it drops to zero, which is the weightlessness astronauts experience. The true weight, mg, is unchanged throughout.