Answer: rate at which energy is being removed is 58.9J/s or 58.9W
Explanation:
Given;
Mass of water Mw =892g = 0.892kg
Mass of aluminium Ma = 214g = 0.214kg
Rate of change in temperature ∆T = 0.9°C per minute
Specific heat capacity of water Cw = 4186J/kgC
Specific heat capacity of aluminium Ca = 900J/kgC
Since both the water and aluminium are at thermal equilibrium and the decrease with the same rate, the energy removed per minute is given as;
Q = (MwCw + MaCa)∆T
Q = (0.892×4186 + 0.214×900)×0.9
Q = 3533.8608J per minute
To determine the energy being removed in watts
P = Q/t
P = 3533.8608J/60s
P = 58.89768W
P = 58.9W
Answer:
The rate at which energy is removed = 59.085 J
Explanation:
The rate at which energy is removed = c₁m₁ΔΘ/t + c₂m₂ΔΘ/t................. Equation 1
Where c₁ = specific heat capacity of the aluminum, m₁ = mass of the aluminum, ΔΘ/t = rate of temperature decrease, c₂ = specific heat capacity of water, m₂ = mass of water.
Given: m₁ = 214 g = (214/1000) kg = 0.214 kg, m₂ = 892 g = (892/1000) kg
m₂ = 0.892 kg, ΔΘ/t = 0.9 °C/min. = (0.9/60) °C/seconds. = 0.015 °C/seconds.
Constants: c₁ = 900 J/kg.°C, c₂ = 4200 J/kg.°C
Substituting these values into Equation 1,
The rate at which Energy is removed = (0.214×900×0.015) + (0.892×4200×0.015)
The rate at which energy is removed = 2.889 + 56.196
The rate at which energy is removed = 59.085 J
