Physics 20.44?
String 1 in the figure has linear density 2.60 g/m and string 2 has linear density 3.30 g/m . A student sends pulses in both directions by quickly pulling up on the knot, then releasing it. She wants both pulses to reach the ends of the strings simultaneously.
https://dl.dropboxusercontent.com/u/252356104/knig...
What should the string length L1 be?
What should the string length L2 be?
Answers & Comments
v = √[T / μ]
T is the tension
μ = mass per unit length of the string
T is the same in both strings for equilibrium
=> for string i => vᵢ = √[1000T / 2.60] = 19.612√T
vᵢᵢ = √[1000T / 3.30] = 17.408√T
time = distance / speed
if string i is 'x' metres.
=> x / [19.612√T] = [4 - x]/ [17.408√T]
=> 17.408x = 19.612(4-x)
=> 37.02x = 78.448
=> x = 78.448 / 37.02 = 2.119 m
Ans: string i is 2.119 m and string ii (4 - 2.119) = 1.881 m
hope this helps