Q 11-04-030NEETEAMCET 2009 (Medical)Easy
A boy of mass $50$ kg is standing on a weighing machine placed on the floor of a lift. The machine reads his weight in newtons. The reading of the machine if the lift is moving upwards with a uniform speed of $10\ \text{m s}^{-1}$ is ($g = 9.8\ \text{m/s}^2$)
Answer: (C) $490$ N
Concept. Uniform velocity means zero acceleration, so $N = mg$.
Step 1. Reading. $50 \times 9.8 = 490$ N.
Answer. $490$ N (Option C).
Solution by Sreeraj P, M.Sc Physics