# Physics Lab Report

Pages: 5 (1069 words) Published: February 16, 2013
Physics Lab Report|
Specific Heat Capacity of Brass|
|
Jin Jin Shi|
2012/12/6|

Instructor: Mr. Nailer|

I. Introduction
The amount of heat required to raise the temperature of a solid body depends on its change in temperature (ΔT), its mass (m), and an intrinsic characteristic of the material forming the body called specific heat (cp). The heat is calculated from the equation II. Purpose

The purpose of this laboratory is to determine the experimental quantities of heat transfer and specific heat capacity in a laboratory situation..

III. Equipment
* Eye protection
* Thermometer
* Stirring rod
* 250 mL beaker
* Retort stand
* Ring clamp
* Hot plant
* 100g brass object
* Tongs
* 2 Styrofoam cups
IV. Experimental Procedure
* Part A: Determining Heat Exchange
1. Put on your eye protection.
2. Use a graduated cylinder to measure 100 mL of cold tap water and place it in a Styrofoam cup. Measure and record the temperature of the cold water in a copy of Table 1. 3. Measure 100 mL of hot tap water and place it in a separate Styrofoam cup. Measure and record the temperature of the hot water in Table 1. 4. Pour the cold water into the hot water. Put the thermometer in the cup and use the stirring rod to mix the water. Watch the temperature carefully and record the highest temperature reached in table 1. * Part B: Determining the Specific Heat Capacity of Brass 1. Place the hot plate on a retort stand with a ring clamp. The ring clamp should be positioned so that the top of the beaker is held in place by the ring. 2. Fill the 250 mL beaker one third full with tap water. Place it inside the ring over the hot plate. 3. Use the balance to measure the mass of 100g brass object and record the mass in a copy of Table 2. 4. Place the brass object in the beaker of water on the hot plate. Turn on the hot plate and let the water come to boil. 5. While waiting, measure 100 mL of cold tap water using a graduated cylinder. Put the cold water into Styrofoam cup and take its temperature. Record this value. 6. Once the water on the hot plate boils, use the thermometer to measure its temperature. Assume that the temperature of the brass is equal to the temperature of the boiling water. This is the initial temperature of the brass. Turn off the hot plate. 7. Using a pair of tongs, remove the brass object from the boiling water and put it in the Styrofoam cup containing the cold water. 8. Gently stir the water surrounding the brass object with a stirring rod and take its temperature with a thermometer. Record the highest temperature reached. V. Tables

* Data Table 1

Purpose: to determining the Heat Exchange
| Temperature (°C)|
Cold Water| 21|
Hot Water| 67|
Mixed Water| 43|

* Data Table 2

Data for Specific Heat Capacity of Brass
| Water| Brass| Unknown Metal|
Mass(kg)| 0.1| 0.1| 0.1|
Initial temperature(°C)| 98| 98| 98|
Final temperature(°C)| 84| 30| 37|

VI. Questions

1. Use the equations Q = mc△T and Qreleased + Qabsorbed=0 to calculate the final temperature of the mixed water. Q = T * m * c where m = 100 g of water and c = 4.18J/kg°C T * m * c(cold water)+T * m * c(hot water)=0

(0.1kg)*( 4.18x10^3J/kg°C)*(Tf-21)=(0.1kg)*( 4.18J/kg°C)*(67-Tf) Tf-21=67-Tf
2Tf=67+21
Tf=44°C
2. Use the percentage difference equation to determine the difference between the measure value and the calculated value:

%difference =measured value – calculated value/measured value*100%

%difference= (43-44)/43*100%

=2.33
3. Use the equations Q = mc△T and Qreleased + Qabsorbed=0 to calculate the specific heat capacity of brass. This is the measure value for the specific heat capacity of brass. Qwater = cp waterx mwater x ΔT water

Qwater= Qbrass...