Question

Two identical masses of $5kg$ each fall on a wheel from a height of $10m$. The wheel disturbs a mass of $2kg$ water, the rise in temperature of water will be:

• A. ${2.6}^{\circ }C$
• B. ${1.2}^{\circ }C$
• C. ${0.32}^{\circ }C$
• D. ${0.12}^{\circ }C$

Answer 1

Answer: (D)

${0.12}^{\circ }C$

Given,

$m=5kg$

$M=2kg$

$h=10m$

$g=10m/s^2$

$J=4.2joule$

We know that,

$W=JQ$

$2mgh=JMs\Delta T$

$\Delta T=\frac{2mgh}{JMs}$

$\Delta T=\frac{2\times 5\times 10\times 10}{4.2\times 2\times 1000}$

$\Delta T={0.12}^{0}C$

The correct option is D.