Kirsten’s mass is 3.73 slugs. Being the physics fan that she is, she decides to see what her apparent weight will be during an elevator ride. Beginning at rest, the elevator accelerates upward at 4.50 ft/s2 for 3.00 s and then continues at a constant upward velocity. Finally, as the elevator comes to a stop at the top floor, the elevator slows down (accelerates downward but continues to move upward) at a rate of 􏰌5.5 ft/s2 (the negative sign represents the downward direction). Find Kirsten’s weight while the elevator is (a) at rest. (b) speeding up. (c) moving at a constant velocity. (d) slowing down. The next time you ride in an elevator, concentrate on when you feel heavier and when you feel lighter.

Answer 1

g = 32.2 ft/s

(a) 3.73 * 32.2 = w (lbs)

(b) 3.73 * (32.2 + 5.5) = w

(c) same as (a)

(d) 3.73 * (32.2 - 5.5) = w