Question Detail
Question
A load of 100 kg is placed on the elevator of mass 700 kg. Find the acceleration of the elevator when originally moving downward at 10 m/s is brought to rest with constant acceleration in a distance 20 m.
Correct Answer
Option A is the correct answer.
Detailed Explanation
Using v² = u² + 2as, with u = -10 m/s (downward), v = 0, s = 20 m. 0 = 100 + 2a(20) → -100 = 40a → a = -2.5 m/s². Magnitude = 2.5 m/s² upward.
Hint
v² = u² + 2as, watch sign convention.