Answer: 0.02kg
Explanation:
The quantity of heat energy (Q) required to heat a substance depends on its Mass (M), specific heat capacity (C) and change in temperature (Φ)
Thus, Q = MCΦ
Since,
Q = 50 joules
Mass of iron sample = ? (let unknown value be Z)
C = 100 J/kg°C
Φ = 25°C
Then, Q = MCΦ
50J = Z x 100 J/kg°C x 25°C
50J = 2500J/kg x Z
Z = (50J/2500J/kg)
Z = 0.02kg
Thus, the mass of the iron sample is 0.02kg