Question

A copper water tank of mass 20 kg contains 150 kg of water at 15°C calculate the energy needed to heat the water and the tank to 55°C

copper shc - 385j/kg
water shc - 4200j/kg

Answer 1

Answer: 25230800 Joules

Explanation: We can treat the copper tank and the water inside as two different objects since they have different specific heats. We will utilize Q=Mcdelta(t) in this problem where M is mass, c is specific heat, and delta t is the change in temperature.

Since we are treating the copper and water separately we can make a Mcdelta(t) for each one of them. This gives us Q=(mass of copper)(specific heat of copper)(delta(t))+(mass of water)(specific heat of water)(delta(t)). The delta t will be the same because both the copper and water are at 15 celsius. Now we just do some calculations.

Q=(mass of copper)(specific heat of copper)(delta(t))+(mass of water)(specific heat of water)(delta(t))

Q=(20)(385)(55-15)+(150)(4200)(55-15)

Q=30800+25200000

Q=25230800 J

This number may seem absurdly high but there is 150 kg of water being heated up which is 150 liters(A LOT!).

Hope this helps!