Gwhen a laser light of unknown wavelength is passed through two narrow slits separated by 150 μm, an interference pattern is observed on a screen 1.5 m away. the distance between the central spot and first order constructive interference is found to be 5 mm. a) find the wavelength of the laser light, in nanometers. (b) at what angle, in degrees, from the central spot is the second-order constructive interference formed?

Answertraveling around a circular trackexplanation"traveling around a circular track" is the best answer as you could be traveling around a circular track at a constant speed. your velocity would therefore have the same magnitude but will always be constantly direction. since acceleration is the rate of change of velocity, the rate of change will only involve the direction of velocity and not the magnitude.wrong choices: "an object at rest" does not accelerate at all"increasing speed while traveling around a curve" means that the acceleration will not be constant due to only change in direction; it will be constant due to both magnitude and direction"an object in free fall" does not necessarily change direction 

Lexy is correct because angle r is between the incident wave,  n  = 0, and a diffracted wave.