Question

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

a. 1/2 mg
b. 2 mg
c. 3/2 mg
d. m

Answer 1

c. 3/2 mg

Step-by-step 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* \frac 1 2 g`

`F-mg=m* \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.