From the Hooke's law , the extension force of an elastic material is directly proportional to the extension.
That is, F = k e, where F is the force , k is the constant and e is the extension
F = 10 × 10 = 100 N
e = 1mm or 0.001 m
Hence, k = F/e
= 100 N/ 0.001
= 100000 N/m or 100 N/mm
Wavelength of any wave = (speed) / (frequency)
Speed of light = 300,000,000 m/sec
Wavelength = 3 x 10 to the 8 / 750 x 10 to the 12 = 4 x 10 to the -7 or 400 nanometers.
(-5)/3 - 6/(-5)
You can solve it now :)
I think the answer is 2 hope it helps