Railways
NTPC (Technical Ability)
Engineering Mechanics and Strength of Materials
Question Bank
Engineering Mechanics
question_answer
A man is pulling a bucket of water up to the roof of a building of 6 m height. The total weight of the rope is 20 N and the weight of the bucket with water is 100 N. The work done by the man is:
A)720 N-m
B)420 N-m
C)660 N-m
D)600 N-m
Correct Answer:
C
Solution :
Total work done \[=100\times 6+\frac{1}{2}\times 20\times 6\] = 660 Nm