Question

help guys iys urgent

Answer 1

Frequency =100 times

=> 0.5 m long =wavelength /2
=> wavelength=0.5×2=1 m

Now velocity = wavelength × Frequency=100×1=100 m/s

After stretched,
=> 0.4 m long =wavelength /2
=> wavelength=0.4×2=0.8m

=>New frequency = velocity /new wavelength
=>New frequency =100/0.8 = 125 times