Q. A system is given 300 calories of heat and it does $600\ joules$ of work. How much does the internal energy of the system change in this process $(J = 4.18joules/cal)$
A) $654\ joule$
B) $156.5\ joule$
C) $- 300\ joule$
D) $- 528.2\ joule$
Explanation
(a) $J\mathrm{\Delta}Q = \mathrm{\Delta}U + \mathrm{\Delta}W,\ \mathrm{\Delta}U = J\mathrm{\Delta}Q - \mathrm{\Delta}W$
$\mathrm{\Delta}U = 4.18 \times 300 - 600 = 654\ joule$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.