- #1
Vanessa Avila
- 94
- 1
Homework Statement
A 1.60-m string of weight 1.30 N is tied to the ceiling at its upper end, and the lower end supports a weight W. When you pluck the string slightly, the waves traveling up the string obey the equation y(x,t)=(8.50mm)cos(172rad⋅m−1(x)−2730rad⋅s−1(t))
a) How much time does it take a pulse to travel the full length of the string?
b) What is the weight W?
c) How many wavelengths are on the string at any instant of time?
Homework Equations
Acos2π(x/λ- t/T)
k = 2π/λ
w = 2π/T
v =√(F/μ)
The Attempt at a Solution
I found the mass of the string by using F = mg and got 0.133 kg. With this mass, I was able to find the density (m/L) which is 0.0831m/kg
for the time, I thought i should do
2730rad/s = 2π/T
T = 2π/2730 rad/s
for how many wavelengths, I thought of doing:
172rad/m = 2π/λ
λ = 2π/172 rad/m, but that was wrong.