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A) Find the energy needed to heat a tank holding water of 60 kg to rise the temperature from 10 degree Celsius to 60 degree Celsius (c=4200 j/Koc)

b)find the time for rising this much temperature if the power of heater is 3kW

User Jbryson
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1 Answer

3 votes

Answer:

a) Q = 12600000 [J]

b) t = 4200 [s] or 70 [min]

Step-by-step explanation:

To solve this problem we must use the following equation that is defined as the heat equation, this equation relates the mass to the specific heat and temperature changes.

Q = m*Cp*(T_f - T_i)

where:

Q = energy as heat [J] (units of Joules)

Cp = specific heat = 4200 [J/Kg * °C]

T_f = final temperature = 60 [°C]

T_i = initial temperature = 10 [°C]

m = mass = 60 [kg]

Q = 60*4200*(60 - 10)

Q = 12600000 [J]

b)

To calculate the time, we know that the power is equal to the energy generated over the given time.

P = Q/t

where:

P = power = 3000 [W]

t = time [s]

t = Q/P

t = 12600000/3000

t = 4200 [s] or 70 [min]

User Anton Rusak
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