Light is incident along the normal to face ab of a glass prism of refractive index 1.54. find αmax, the largest value the angle α can have without any light being refracted out of the prism at face ac if the prism is immersed in water (with index of refraction 1.33). express your answer in degrees. ignore any reflections from the surface bc.
distance is the total length of an object's path. displacement is the overall change in position, ie. how far an object is from its initial position.
the court is 30 m long, so a path going back and forth once is 60 m long. going along this path 6 times totals 360 m.
the end point is the same as the starting point, so the displacement is 0 m.
velocity = displacement / time
displacement measures how far the ending point is from the starting position. if the object returns to its original position, displacement will be 0 m.
in the question, the object starts at p and returns to p, so displacement equals 0 m. thus, no matter how long the travelling time is, the average velocity is also 0 m/s.
so, the ans is a.