Physics Lab Question - High School

[PlanetLazy]

In my introductory physics class in high school we did a lab on specific heat. We heated metals and placed them into cool water and observed the temperature change to find the specific heat of the metal. One of the questions on the lab puzzled me.
- Why was the cool water purposely started well below room temperature?
What is the reason for having the water below room temperature?

 

[ehild]

What was the final temperature of water after adding the metal piece? Was it above room temperature?

ehild

 

[PlanetLazy]

What was the final temperature of water after adding the metal piece? Was it above room temperature?

ehild

it was between 26 - 30 degrees celsius which is a little above room temperature.

 

[ehild]

The water exchanges some heat with the surroundings. If the water is initially at room temperature, it losses heat all the time during the metal warms it up. That causes error in the final temperature.

If you start below room temperature, the water gets heat from the surroundings first, and when it warms above room temperature, it losses heat. The gain and loss about cancel each other.
The best is when you find a balance, so as the room temperature is halfway between the initial and final temperature of water.

ehild

 

[PlanetLazy]

thank you very much and great explanation!