Work Energy And Power Question 228
A block of 1 kg is kept on a rough surface of an elevator moving up with constant velocity of 5m/s. In 10 seconds work done by normal reaction (the block does not slide on the inclined surface)
(i) from ground frame is 320 J
(ii) is equal to work done by friction force in elevator frame
(iii) the work done by friction in the ground frame is equal to the work done by the force in the ground frame, the one that is true is given by the choice
Options:
A) Only (i)
B) (ii) and (iii)
C) (i) and (ii)
D) only (iii)
Show Answer
Answer:
Correct Answer: C
Solution:
[c] W.D. from ground frame $ =6.4\times 50= 320 J $
From elevator frame, displacement = 0.
$ N cos 37{}^\circ = 8\times 0.8 = 6.4 N $
BETA
