Question

Eric, whose mass is 50 kg, is in an elevator descending at 10 m/s. The elevator takes 2.0 s to brake to a stop on the first floor. What is Eric’s apparent weight while the elevator is braking? Group of answer choices 240 N 196 N 740 N 490 N

Answer 1

The only forces that affect Eric are the tension that the cable exerts on the elevator and the gravitational force. Applying Newton's second law we can determine the forces that only act on the yy axis:

To determine Eric's weight when the elevator is going down, we must determine the tension T exerted by the cable that supports the elevator.

where m is the mass, g is the gravity and a is the acceleration. We will determine the acceleration by applying the following equation:

Acceleration is taken negative since the elevator goes down.