Two identical metal blocks start at

PHYSICS · Single correct · A Level · Physics · Further mechanics and thermal physics · Further mechanics and thermal physics

Problem

Two identical

100\,\text{g}

metal blocks start at

25\,^{\circ}\!\text{C}

. Metal X has a specific heat capacity of

0.25\,\text{J}\,\text{g}^{-1}\,^{\circ}\!\text{C}^{-1}

, and metal Y has a specific heat capacity of

0.50\,\text{J}\,\text{g}^{-1}\,^{\circ}\!\text{C}^{-1}

. Each block is heated by its own electric coil that supplies a constant

40\,\text{J}\,\text{s}^{-1}

. At the instant metal Y reaches

75\,^{\circ}\!\text{C}

, what is the temperature of metal X? (a)

150\,^{\circ}\!\text{C}

(b)

125\,^{\circ}\!\text{C}

(c)

100\,^{\circ}\!\text{C}

(d)

75\,^{\circ}\!\text{C}