Dispersion occurs due to the different degrees of refraction experienced by different colours of light. Light of different colours may travel with the same speed in a vacuum, but they travel at different speeds in some refracting medium. The speed of violet light is relatively lower than that of red light.
Hello!!
For calculate the work let's applicate the formula:
W = Work = ?
F = Force = 1525 N
d = Distance = 381 m
⇒ 
W = 1525 N * 381 m
⇒ 
W = 581025 J
