Answer:
61578948 m/s
Explanation:
λ
= λ

687 = 570 
= 61578948 m/s
So Slick Willy was travelling at a speed of 61578948 m/s to observe this.
The bus and the truck have the same velocity.
Also, Valerie and Owen have the same velocity.
The index of refraction of a material is the ratio between the speed of light in vacuum, c, and the speed of light in that material, v:

where the speed of light in vacuum is

. The speed of light in benzene is

, so we can use the previous relationship to find the refractive index of benzene:
Answer:
shown in the attachment
Explanation:
The detailed step by step and necessary mathematical application is as shown in the attachment.