Height of a waterfall is 84 metre. Assuming that entire kinetic energy of falling water is converted

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10-1.Thermometry, Thermal Expansion and Calorimetry

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The height of a waterfall is $84$ metre. Assuming that the entire kinetic energy of falling water is converted into heat, the rise in temperature of the water will be $(g = 9.8\,m/{s^2},\;J = 4.2\,joule/cal)$

A

$0.196°C$

B

$1.960°C$

C

$0.96°C$

D

$0.0196°C$

Solution

(a) $W = JQ$ $\Rightarrow$ $mg\,h = J(m.c.\Delta \theta )$

$\Rightarrow$ $\Delta \theta = \frac{{g\,h}}{{Jc}} = 0.0023\,h = 0.0023 \times 84 = 0.196^\circ C$

Standard 11

Physics

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