Two identical blocks of metal are at 20^{circ | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(B) When two blocks are brought into contact,the hotter block loses heat and the colder block gains heat.Let $T_f$ be the final equilibrium temperatur

Vedclass · Accepted Answer

$T_f$ will be more than $50^{\circ} C$

Vedclass · Answer

(B) When two blocks are brought into contact,the hotter block loses heat and the colder block gains heat.Let $T_f$ be the final equilibrium temperature.According to the principle of calorimetry,heat lost by the hotter block equals heat gained by the colder block.$m \int_{T_f}^{80} s(T) dT = m \int_{20}^{T_f} s(T) dT$Since the specific heat $s(T)$ is an increasing function of temperature,the average specific heat of the hotter block (in the range $T_f$ to $80^{\circ} C$) is greater than the average specific heat of the colder block (in the range $20^{\circ} C$ to $T_f$).Let $s_{avg, hot}$ be the average specific heat of the hotter block and $s_{avg, cold}$ be the average specific heat of the colder block. Then $s_{avg, hot} > s_{avg, cold}$.$s_{avg, hot} (80 - T_f) = s_{avg, cold} (T_f - 20)$$\frac{80 - T_f}{T_f - 20} = \frac{s_{avg, cold}}{s_{avg, hot}} $80 - T_f $100 $T_f > 50^{\circ} C$Therefore,the final temperature will be more than $50^{\circ} C$.

Similar Questions

Of two masses of $5 \, kg$ each falling from a height of $10 \, m$,by which $2 \, kg$ of water is stirred. The rise in temperature of the water will be ........ $^\circ C$.

We have half a bucket $(6 \text{ litre})$ of water at $20^{\circ}C$. If we want water at $40^{\circ}C$,how much steam at $100^{\circ}C$ should be added to it?

The thermal capacity of a body is $80 \, cal/^{\circ}C$. What is its water equivalent?

$A$ metal block of mass $3.3 \ kg$ is heated to a temperature of $400^{\circ} C$ and then placed on a large ice block. The specific heat of the metal is $0.4 \ J \ g^{-1} \ K^{-1}$ and the latent heat of fusion of water is $330 \ J \ g^{-1}$. The maximum amount of ice that can melt is: (in $kg$)

Vedclass Test Series

Exam Paper Generator

Online Exam Module