Q. Of two masses of $5\ kg$ each falling from height of $10\ m,$ by which $2kg$ water is stirred. The rise in temperature of water
A) $2.6℃$
B) $1.2℃$
C) $0.32℃$
D) $0.12℃$
Explanation
(d) $W = JQ \Rightarrow (2m)gh = J \times m'c\mathrm{\Delta}\theta$
$\Rightarrow 2 \times 5 \times 10 \times 10 = 4.2(2 \times 1000 \times \mathrm{\Delta}\theta)$
$\Rightarrow \mathrm{\Delta}\theta = 0.1190℃ = 0.12℃$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.