Mass m of a liquid A is kept in a cup at a temperature of 90∘C. When placed in a room having temperature of 20∘C, it takes 5 min for the temperature of the liquid to drop to 30∘C. Another liquid B having nearly the same density as A and of mass m, kept in another identical cup at 50∘C takes 5 min for its temperature to fall to 30∘C when placed in a room having temperature 20∘C. If the two liquids at 90∘C and 50∘C are mixed in a calorimeter where no heat is allowed to leak, find the final temperature of the mixture. Assume that Newton's law of cooling is applicable for the given temperature ranges.

Mass m of a liquid A is kept in a cup at a temperature of 90∘C. When

1.	Mass m of a liquid A is kept in a cup at a temperature of 90∘C. When placed in a room having temperature of 20∘C, it takes 5 min for the temperature of the liquid to drop to 30∘C. Another liquid B having nearly the same density as A and of mass m, kept in another identical cup at 50∘C takes 5 min for its temperature to fall to 30∘C when placed in a room having temperature 20∘C. If the two liquids at 90∘C and 50∘C are mixed in a calorimeter where no heat is allowed to leak, find the final temperature of the mixture. Assume that Newton's law of cooling is applicable for the given temperature ranges.
Answer» Mass $m$ of a liquid $A$ is kept in a cup at a temperature of $90^{\circ} C$ . When placed in a room having temperature of $20^{\circ} C$ , it takes $5 min$ for the temperature of the liquid to drop to $30^{\circ} C$ . Another liquid $B$ having nearly the same density as $A$ and of mass $m$ , kept in another identical cup at $50^{\circ} C$ takes $5 min$ for its temperature to fall to $30^{\circ} C$ when placed in a room having temperature $20^{\circ} C$ . If the two liquids at $90^{\circ} C$ and $50^{\circ} C$ are mixed in a calorimeter where no heat is allowed to leak, find the final temperature of the mixture. Assume that Newton's law of cooling is applicable for the given temperature ranges.

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