Question Detail
Question
A boy is standing on a bathroom scale in an elevator car. If the scale reads a value greater than the weight of the person at rest, the elevator car could be moving
Correct Answer
Option D is the correct answer.
Detailed Explanation
The scale reads the normal force. When the elevator accelerates upward, the normal force exceeds the weight (N = m(g+a)). So the scale reads more. This can happen when the elevator is moving upward and increasing speed (accelerating upward) or moving downward and decreasing speed (decelerating downward). Among the options, only 'upward at increasing speed' corresponds to upward acceleration.
Hint
Apparent weight is greater than true weight when the elevator accelerates upward.