Solving a Physics Problem: Transverse Wave Travel Time

[lmar769]

Homework Statement

Algebra based physics: A 23 kg mass is suspended from the bottom of a rope of length 2.4 m and mass 17 kg. The acceleration of gravity is 9.8 m/s^2.
Find time for a transverse wave to travel the length of the rope. Answer in units of sec.

Homework Equations

u= mass rope/ length rope
F=mg
v= d/t

The Attempt at a Solution

u= 17kg / 2.4m = 7.0833333

v= sqr (17+23)(9.8)/7.0833333
v= 7.439165039

t= d/v
t= 2.4m / 7.439165039
t= 0.322616851 s

This answer is wrong and I've had 2 tutors look over this but couldn't figure where the problem is.

 

[Gear300]

The mass of the rope is the medium the tension distributes across but it is not the source of the tension...although, if you want to be a bit more certain...you could use a bit of calculus to find the tension at various parts of the rope (it does change along its length...but you probably don't need to take this into account).