Answer:
v= 35.09m/s
f= 38.77Hz
Step-by-step explanation:
Length 'L' = 1.81 m
Now, First off the fourth harmonic of a string with two nodes is given by:
L=2λ
1.81=2λ
λ= 1.81/2 =>0.905 m
Wave speed on a strecthed string is:
v=√(Ft/(m/l))
v= √(8.37)/(0.0123/1.81)
v= 35.09m/s
Next is to determine frequency i,e
v=λf or f =v/λ
f= 35.09/0.905
f= 38.77Hz