Q1. A diffraction grating with exactly 1000 lines per centimeter is illuminated by a He-Ne laser of wavelength 683 nm.
What is the highest order of diffraction that could be observed with this grating?
Q2. A 6.4kg ball, hanging from the ceiling by a light wire 135cm long, is struck in an elastic collision by a 1.80 ball moving horizontally at 4.20 m/s just before the collision. Find the tension in the wire just after the collision.