A person of mass 70 kg is inside an elevator in free fall. A spring dynamometer hangs from the ceiling of the elevator. If the occupant of the elevator holds on to the dynamometer, the dynamometer will read a weight of (g = 10 m/s2):

When the elevator is in free fall, it means that the net force acting on the person inside the elevator is zero. This is because the gravitational force pulling the person downward is balanced by the upward force exerted by the elevator.

Since the person is not accelerating, is falling under his own weight, the dynamometer will read the person's weight. The weight of the person is given by the formula:

Weight = mass × acceleration due to gravity.

In this case, the mass of the person is 70kg,and the acceleration due to gravity is 10m/s².

Weight = 70kg × 10m/s²

Weight = 700N.

Therefore, the dynamometer will read a weight of 700N

MathPhys MathPhys · Answer 2 · 2024-07-11T10:38:47-04:00

Answer:

Zero

Explanation:

A scale, such as a spring dynamometer, works by measuring the apparent weight, which is the magnitude of the normal force exerted by the surface. For a person in free fall, the only force is the force due to gravity, so there is no normal force. Therefore, the dynamometer will read a weight of zero. This is the same reason astronauts are "weightless" as they orbit the Earth. Because they are in constant free fall, their apparent weight is zero.