Final answer:
The scale reading with Eric's 60 kg mass in a downward-accelerating elevator would show his apparent weight, which is calculated as his true weight minus the force due to the elevator's acceleration. After calculation, the approximate scale reading is found to be 500 N, which is answer option C.
Step-by-step explanation:
To determine the scale reading of Eric's weight when the elevator is accelerating downward, we need to consider the net force acting on him. Normally, the scale reads a person's true weight, which is the force due to gravity. However, that reading changes if the elevator accelerates because the net force is altered.
In this case, the elevator is accelerating downward at 1.7 m/s2, reducing the net force that the scale exerts on Eric. To find the reading, we calculate the apparent weight using the following equation:
- Apparent weight = True weight - Force of acceleration
Eric's true weight is the product of his mass and gravitational acceleration:
True weight (W) = mass (m) × gravity (g)
W = 60 kg × 9.8 m/s2 = 588 N
The force of acceleration (Fa) is his mass times the elevator's acceleration:
Fa = m × acceleration (a)
Fa = 60 kg × 1.7 m/s2 = 102 N
The scale reading, which is his apparent weight, is thus:
Apparent weight = 588 N - 102 N = 486 N
The closest answer to 486 N is C) 500 N, so the approximate reading on the scale when the elevator is accelerating downward at 1.7 m/s2 would be about 500 N.