JEE Main & Advanced
Physics
NLM, Friction, Circular Motion
Question Bank
Second Law of Motion
question_answer
A man weighs \[80kg.\] He stands on a weighing scale in a lift which is moving upwards with a uniform acceleration of \[5m/{{s}^{2}}.\] What would be the reading on the scale. \[(g=10m/{{s}^{2}})\] [CBSE PMT 2003]
A) 400 N
B) 800 N
C) 1200 N
D) Zero
Correct Answer:
C
Solution :
For accelerated upward motion \[R=m\,(g+a)=80\,(10+5)=1200\,N\]