Answer: speed of vibration = 146.33m/s
Explanation: The speed of sound (v) in a string is related to tension (T) and mass per unit length (u) via the formula
v = √T/u
T = 621N, m =32.4g = 0.0324kg, l= 1.12m
u = mass / length, thus
u = 0.0324/ 1.12 = 0.029kg/m
Hence
v = √621/ 0.028
v = √ 21,413.793
v = 146.33m/s