Question

Suppose the acceleration of an elevator is 1/2 g upward, then what is the reading on the scale in the elevator.

Answer 1

Answer:

c. 3/2 mg

Explanation:

Given that the acceleration of an elevator is 1/2 g upward.

The reading on the scale of the elevator is the net external force acting on the elevator.

Let the force F acting on the elevator as shown,

By using Newton's 2nd law, $F_{net}=ma$

where, $F_{net}$ is the net force acting on the elevator.

m is the mass of the elevator,

a is the acceleration of the elevator, as given a=1/2 g upward.

So, $F_{net}=m\times \frac 1 2 g$

$F-mg=m\times \frac 1 2 g \\\\F=mg+ \frac 1 2 mg \\\\F= \frac 3 2 mg.$

So, the reading on the scale in the elevator is $\frac 3 2 mg$.

Hence, option (c) is correct.