Carnot Heat Engine

1. Nov 9, 2011

tehjojo

1. The problem statement, all variables and given/known data

Consider a Carnot engine that operates between a hot reservoir at 63°C and a cold reservoir at -14°C. In running 25 minutes, this engine absorbs 590 J of heat from the hot reservoir.

How much heat does it expel to the cold reservoir?

2. Relevant equations
$$Q_H/Q_C = T_H/T_C$$
3. The attempt at a solution
$$T_H = 336k$$
$$T_C = 287k$$
$$Q_H/Q_C = T_H/T_C \longrightarrow 590/Q_C = 336/287$$
Solving for $$Q_C$$ I get 504 J, however, this is not the correct answer. What am I missing?

2. Nov 10, 2011

RTW69

Are you sure Tc= 287 K? The cold reservoir is at -14 C

3. Nov 10, 2011

tehjojo

Wow. It happened that on the site my homework is on, the negative sign and the number were on different lines, so I totally missed it. Thank you very much.