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Mechanical MET1

During a heat treatment process, a piece of steel of mass 2.0kg is heated to 770 degrees Celsius and plunged into oil at a temperature of 20 degrees.the final steady temperature is 45 degrees Celsius the specific heat capacities of steel and oil are 460j/kgk and 1850j/kgk respectively calculate the mass of the oil used.

Reply 1

IJaguar

Would you still like help with this question?

If I were doing this question, I would develop some equations.

The heat energy of each thing is equal to their mass * temperature * heat capacity
The mass of steel is 2kg, its initial temperature is 770 degrees and its heat capacity is 460j/kgk and so its heat energy is 708,400J
The mass of the oil is unknown (we can call it x), its initial temperature is 20 degrees and its heat capacity is 1850j/kgk and so its heat energy is 37,000xJ
Resultantly, the total heat energy is 708,400 + 37,000x J

At the end:
The mass of steel is still 2kg, its temperature is 45 degrees and its heat capacity is still 460j/kgk and so its heat energy is 41,400J
The mass of the oil is still unknown, its temperature is 45 degrees and its heat capacity is still 1850j/kgk and so its heat energy is 83,250x J
Resultantly, the total heat energy is 41,400J + 83,250x J

Since the total heat energy is equal at both the start and the end, we can equate them;

708,400 +37,000x = 41,400 + 83,250x
This should be a lot easier for you to solve