A current carrying wire heats a metal rod. The wire provides a constant power (P) to the rod. The metal rod is enclosed in an insulated container. It is observed that the temperature (T) in the metal rod changes with time (t) as T(t) = T₀(1 + βt¹ᐟ⁴), where β is a constant with appropriate dimension while T₀ is a constant with dimension of temperature. The heat capacity of the metal is