A cup of tea at is left to cool in a room maintained at

PHYSICS · Single correct · CBSE · Physics · Thermal Properties of Matter · Thermal Properties of Matter

Problem

A cup of tea at

90^{\circ}\text{C}

is left to cool in a room maintained at

25^{\circ}\text{C}

. Its temperature drops to

70^{\circ}\text{C}

after

5

minutes. Find the cooling constant

k

(correct to three decimal places). (a)

0.054\,\text{min}^{-1}

(b)

0.074\,\text{min}^{-1}

(c)

0.032\,\text{min}^{-1}

(d)

0.062\,\text{min}^{-1}