An emergency field stove is capable of releasing of energy from its fuel cartridge

PHYSICS · Multi-part · AP · Physics 2: Algebra-based · Thermodynamics · Thermodynamics

Problem

An emergency field stove is capable of releasing

2.0\,\text{MJ}

of energy from its fuel cartridge. A camper wants to use the stove to heat liquid water (initially at

22\,^{\circ}\text{C}

) for cooking. The target temperature is

78\,^{\circ}\text{C}

. Take the specific heat of liquid water to be

4.18\times10^{3}\,\text{J}\,(\text{kg}\,^{\circ}\text{C})^{-1}

and neglect any energy losses to the environment. (a) Determine the maximum mass of water that can be brought from

22\,^{\circ}\text{C}

78\,^{\circ}\text{C}

with the available energy. (b) If the initial water temperature were

10\,^{\circ}\text{C}

instead, would the same fuel cartridge be sufficient to heat the mass calculated in part (a) to

78\,^{\circ}\text{C}

? Justify your answer quantitatively.