Q1. A gadget of mass 17.52kg floats in space without motion. Because of some internal malfunction the gadget violently breaks up into 3 fragments flying away from each other. The first fragment has a mass m1 = 6.77kg and speed v1 = 6.22 m/s as the second has mass m2 = 5.1kg and speed v2 = 2.87 m/s. The angle between the velocity vectors v1 and v2 is 43. What is the speed of v3 of the third fragment?
Q2. Coherent light with wavelength 599nm passes through two very narrow slits, and the interference pattern is observed on a screen a distance of 3.00m from the slits. The first-order bright fringe is a distance of 4.84mm from the center of central bright fringe.
For what wavelength of light will the first-order dark fringe be observed at this similar point on the screen?