Answer: 9.8N
Explanation: The velocity of a sound wave (v), tension on the string (T) and mass per unit length (u) are all related by the formulae below
T = v² * u
Where T is tension in Newton (N), v is velocity of sound waves in meter per seconds (m/s) and u is mass per unit length in kilogram per meter (kg/m)
u = mass of chord / length of chord
u = 0.44/ 8.1
u = 0.1 kg/m
Velocity of sound waves (v) =length of chord / time taken for wave to travel
v = 8.1 / 0.82 = 9.9m/s
Tension is calculated below using the formula
T = v² * u
T = (9.9)² x 0.1
T= 9.8N
