Question

question 7 (1 point)
a person on a scale rides in an elevator. if the mass of the person is 60.0 kg and the elevator accelerates downward with an acceleration of 4.90 m/s2, what is the reading on the scale?
147 n
294 n
588 n
882 n

Explanation:

Step1: Recall Newton's second law for the elevator problem.

The apparent weight (scale reading) \( F_N \) when an elevator accelerates downward is given by \( F_N = m(g - a) \), where \( m \) is mass, \( g = 9.80 \, \text{m/s}^2 \) (acceleration due to gravity), and \( a \) is the elevator's acceleration.

Step2: Substitute the given values.

Given \( m = 60.0 \, \text{kg} \), \( a = 4.90 \, \text{m/s}^2 \), \( g = 9.80 \, \text{m/s}^2 \).
Substitute into the formula:
\( F_N = 60.0 \times (9.80 - 4.90) \)
First, calculate \( 9.80 - 4.90 = 4.90 \, \text{m/s}^2 \).
Then, \( F_N = 60.0 \times 4.90 = 294 \, \text{N} \).

Answer:

294 N (corresponding to the option: 294 N)