Answer to Question #180320 in Molecular Physics | Thermodynamics for Kurt

Question

To raise the temperature of 5 kg of water from 20 0C to 30 0C, a 2-kg iron bar is heated and then dropped into the water. What should the temperature of the bar be

Answer 1

Heat gained = Heat loss

$m _{w}C_{w}Δθ_{w} = m _{b}C_{b}Δθ_{b}$

where

m = mass ( kg ); mass of water = 5kg, mass of iron bar = 2kg

C = Specific heat capacity; SHC of water = 4182 J/kg°C, SHC of Iron = 462 J/kg°C

Δθ = Temperature change; temperature change in water = 10°C, temperature change in iron bar = $(x- 30)$°C

$5× 4182× 10 = 2 × 462× (x- 30)$

$x - 30 = \frac{209100}{924}$

$\therefore x = 256.3 °C$