An object is cooled from 7 5 ∘ C to 6 5 ∘ C in 2 minutes in a room at 3 0 ∘ C. The time taken to cool the same object from 5 5 ∘ C to 4 5 ∘ C in the same room is:

First: 2 10 = k ( 70 − 30 ) , so k = 8 1 . Second: t 10 = 8 1 ( 50 − 30 ) , so t = 4 minutes. C.

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Physics - Heat & Thermo Question with Solution | TestHub

PhysicsHeat & ThermoHeat TransferMedium2 min

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An object is cooled from $7 5^{\circ}$ C to $6 5^{\circ}$ C in 2 minutes in a room at $3 0^{\circ}$ C. The time taken to cool the same object from $5 5^{\circ}$ C to $4 5^{\circ}$ C in the same room is:

Options:

Answer:

Solution:

First: $\frac{10}{2} = k (70 - 30)$ , so $k = \frac{1}{8}$ . Second: $\frac{10}{t} = \frac{1}{8} (50 - 30)$ , so $t = 4$ minutes. C.

Subject:PhysicsTopic:Heat & ThermoSubtopic:Heat Transfer

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