An Example Lab Report (Page 2 of 5) in pdf

An Example Lab Report Page 2

Speed of Sound in Various Materials

Science of Stuff, ET301

February 30, 2112

Name: Johan Bruhaus

Partner: Gail Faux

Objective

The hypothesis investigated in this exercise is straight-forward, namely that the speed of

propagation of sound depends on the characteristics of the material and that it may be

affected by temperature. Three different materials will be investigated, each at three

different temperatures. It is expected that the velocity in all three materials will be

significantly greater than the velocity of sound in air (343 meters per second).

Conclusion

The speed of sound in a particular material depends on the internal characteristics of the

material. The speed may either increase or decrease with temperature. The velocity at

room temperature for the SB alloy was approximately 2001 meters per second with a

temperature coefficient (TC) of .01%. The GA alloy was 3050 meters per second with -

.2% TC, and the CCCD material was measured at 997 meters per second with .1% TC.

All values were within a few percent of those predicted by theory, and all velocities were

clearly much greater than the velocity of sound in air.

Discussion

To investigate the speed of sound, three bars of material, each one meter long, were

obtained. The first was “Sonic Bronze” or SB, an alloy of tin, copper, zinc, and

porcupinium. The second material, “Green Aluminum” or GA, is an alloy of aluminum

and kryptonite, while the third, CCCD, is commonly known as “Chocolate Chip Cookie

Dough”.

An Example Lab Report Page 2