Laws Of Motion Question 101
Question: A body of mass 2 kg is being dragged with uniform velocity of 2 m/s on a rough horizontal plane. The coefficient of friction between the body and the surface is 0.20. The amount of heat generated in 5 sec is $ (J=4.2joule/cal $ and $ g=9.8m/s^{2}) $ [MH CET (Med.) 2001]
Options:
A) 9.33 cal
B) 10.21 cal
C) 12.67 cal
D) 13.34 cal
Show Answer
Answer:
Correct Answer: A
Solution:
Work done = Force × Displacement$ =\mu \ mg\times (v\times t) $
$ W=(0.2)\times 2\times 9.8\times 2\times 5\ joule $ Heat generated Q$ =\frac{W}{J} $
$ =\frac{0.2\times 2\times 9.8\times 2\times 5}{4.2} $
$ =9.33 $ cal
