Answer:
68.25 kJ
Step-by-step explanation:
The thermal energy Q required to raise the temperature of 15kg gold from 45⁰ C up to 80⁰ C is Q = mcΔθ where m = mass of gold = 15 kg, c = specific heat capacity of gold = 130 J/kg°C and Δθ = temperature change = θ₂ - θ₁ where θ₁ = 45 °C and θ₂ = 80 °C
So, Q = mcΔθ = mc(θ₂ - θ₁)
= 15 kg × 130 J/kg°C × (80 °C - 45 °C)
= 1950 J/°C × 35 °C
= 68,250 J
= 68.25 kJ