Question Detail
Question
A lift moves up with an acceleration of 4 m/s². Calculate the reaction of the floor on an object of mass 50 kg placed on the floor of the lift.
Correct Answer
Option C is the correct answer.
Detailed Explanation
When the lift accelerates upward, the normal reaction N exceeds the weight. Using Newton's second law: N - mg = ma, so N = m(g + a) = 50(9.8 + 4) = 50(13.8) = 690 N. Using g = 10 m/s², N = 50(14) = 700 N. Since the options include 700 N, it's likely they use g = 10 m/s².
Hint
Apply Newton's second law in the non-inertial frame or consider the effective weight in an accelerating lift.