# Homework Help: Standing waves on a string.

1. May 23, 2012

### charmedbeauty

1. The problem statement, all variables and given/known data

During the experiment you will be collecting data similar to that in the table below. The experimental set up is the same as that described in your lab manual. Complete this table. Assume that the frequency is 50 Hz, and is known accurately.

this is the data given.

1 Loop (mm) =48.9 +/- 1.5
2 Loops (mm)=96.4 +/- 2.0
3 Loops (mm)=141.3 +/- 2.0

Hanging mass= 200 +/- 5 (g)

frequency = 50 Hz

Find

1)Wavelength with uncertainty (mm)

2)velocity m/s with uncertainty

3)Tension (N) with uncertainty

2. Relevant equations

3. The attempt at a solution

to find the wavelength

im guessing I should find the average length within the loops.

so...

48.9 + 96.4/2 + 141.3/3 =144.2

144.2/3 = 48.1

λ= 2* (48.1)

λ= 96.1 (is this right??) →how would I find the uncertainty? is it just find λ with the largest value for the length and subtract λ with the smallest length and divide by 2?

v=fλ

v= 50(0.0961)

v= 4.807 m/s (is this right) → is the uncertainty just the uncertainty in λ?

T = mg

T = 0.2 (9.8)

T= 1.96N and uncertainty in T is I'm guessing the uncertainty in mass = 0.005 are these the right units (kg).

Thanks.

2. May 27, 2012

### Simon Bridge

as good as any