To obtain 1800 J of heat, 200 g of iron was heated by 20 ° C. What is the specific heat of iron?

Q = c * m * (t_2 – t_1),

where Q is the amount of heat,
m – body weight,
(t_2 – t_1) – the difference between the initial and final body temperatures,
c – specific heat capacity of the substance;

(t_2 – t_1) = 20 C;

Q = 1800 J;

m = 200 * g = 0.2 kg;

c = Q / m * (t_2 – t_1) = 1800/20 * 0.2 = 450 J / (kg * C)

Answer 450 J / (kg * C)