Question

To measure the specific heat of copper, an experiment is performed in the lab. A piece of copper is heated in an oven then dropped into a beaker of water. To calculate the specific heat of copper, the experimenter must know or measure the value of all the quantities below EXCEPT the
A. Original temperature of the copper and the water
B. Mass of the water
C. Final (equilibrium) temperature of the copper and the water
D. Time taken to achieve equilibrium after the copper is dropped into the water
E. Specific heat of the water

Answer 1

Hint: As we know the formula for the specific heat, that depends on the heat of the substance, mass of substance and the increase in the temperature of substance. Heat lost by the copper will be equal to the heat gain by beaker and water, if the system is insulated.

Complete answer:
Specific heat is the amount of heat per unit mass that is required to raise the temperature of any substance by \[1^\circ C\].
\[\Delta Q = mc\Delta t\]
Here \[\Delta Q\] is the heat energy that is given to the substance.
M is the mass of substance and \[\Delta t\] is the change in temperature.
In this problem, the substance is copper and the experimenter requires the mass of the copper piece but not the mass of the water because water is just dropping the temperature of the copper piece not more than this.

So, the correct answer is “Option D”.

Note:
If we want to calculate the heat lost by copper then we need to insulate the whole system and need to balance the heat. As long as the heat is lost to the surroundings, it does not matter how long it takes to reach equilibrium. So, it is not necessary to measure the time taken for the copper to come in equilibrium with water.