A 70kg student stands on a scale inside an elevator that is moving upward but slowing down at 2.0m/s2. Which of the following best describes the relationship between the upward normal force N exerted by the scale and the student’s weight W at this instant?
a) N is greater than W by 70kg×2.0m/s2
b) N is equal in magnitude to W
c) N is less than W by 70kg×2.0m/s2
d) N is less than W by 70kg×7.8m/s2