Lab#2: Activity P41: Waves on a string
Jonathan Alevy
Physics 1302.101
Partners names: Henry Haws, Johnathan Rios & Miguel Castellano

Pre-Lab
Direct Calculation of the Linear Mass Density
1. Measure the mass of a known of the string. Length = L = 1.77 meters
Mass = M = 5.7 x 10-4 kilograms µ = mass/length = 5.7 x 10-4 / 1.77m= 3.22 x 10-4 kg/m

Table 1: Change Tension – Constant Frequency and Length
Frequency = 120 Hz
Length = 1.0 m

Segments, n
Experimental Mass (kg)
Theoretical Mass (kg)
% difference: Exp-Theo
Tension, T (N)

1/n2
1
1.84
1.89
2.78%
18.0
1.00
2
0.463
0.473
2.14%
4.54
0.250
3
0.207
0.210
1.44%
2.03
0.111
4
0.113
0.118
4.33%
1.11
0.0625
5
0.0720
0.0760
5.41%
0.706
0.0400

Slope= 18
The slope is equal to = 18; = 3.125 x 10-4 kg/m

Linear mass density = 3.125 x 10-4 kg/m

Table 2: Vary Frequency
Tension = 4.9 N Tension = Mass x Gravity = 0.500kg x 9.81m/s2 = 4.9 N
Length = 1.0 m

Segments, n
Experimental Frequency (Hz)
Theoretical Frequency (Hz)
% difference Exp-Theo
0
0
0
0%
1
62.00
61.68
0.520%
2
125.7
123.4
1.88%
3
189.0
185.0
2.12%
4
251.1
246.7
1.76%
5
313.9
308.4
1.77%

Slope = 62.9
The slope is equal to = 62.9; =3.096 x 10-4 kg/m

Linear mass density = 3.096 x 10-4 kg/m

Table 3: Results
Method
Linear mass density
% difference
Direct
3.22 x 10-4

Tension vs. 1/n2
3.125 x 10-4
3.0%
Frequency vs. n
3.096 x 10-4
4.0%

Questions
1. As the tension is increased, does the number of segments increase or decrease when the frequency is kept constant?
The number of segments decreases as tension increases