A body of mass 5 ,kg falls from a height of 30 metre. If its all mechanical energy is changed into h

English

Gujarati

Hindi

10-1.Thermometry, Thermal Expansion and Calorimetry

medium

A body of mass $5 \,kg$ falls from a height of $30$ metre. If its all mechanical energy is changed into heat, then heat produced will be........ $cal$

A

$350$

B

$150$

C

$60$

D

$6$

Solution

(a) $W = JQ$ $\Rightarrow$ $mgh = J \times Q$

$\Rightarrow$ $Q = \frac{{mgh}}{J} = \frac{{5 \times 9.8 \times 30}}{{4.2}} = 350\,cal$

Standard 11

Physics

Share

Similar Questions

The specific heat of alcohol is about half that of water. Suppose you have identical masses of alcohol and water. The alcohol is initially at temperature $T_A$. The water is initially at a different temperature $T_W.$ Now the two fluids are mixed in the same container and allowed to come into thermal equilibrium, with no loss of heat to the surroundings. The final temperature of the mixture will be :-

medium

The height of victoria falls is $63\, {m}$. What is the difference in temperature of water at the top and at the bottom of fall ? (In $^{\circ} {C}$)

[Given $1\, {cal}=4.2\, {J}$ and specific heat of water $\left.=1 \,{cal} \,{g}^{-1}\;{ }^{\circ}\, {C}^{-1}\right]$

medium

(JEE MAIN-2021)

At a power station, heat is removed from the heat exchanger by cooling water at $6.7 × 10^9\ J$ per minute. The cooling water enters at $6.0\ ^oC$ and leaves at $14.0\ ^oC$ . [Take the specific heat capacity of water $4200\ J/kg^oC$ ] Which of the following is the rate of water flow?

medium

The mechanical equivalent of heat $J$ is

easy

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 $(g = 9.8\,m/{s^2},\;J = 4.2\,joule/cal)$

medium