Displacement is the distance and direction from the start point to the end point. Our runner finished exactly where he started. His displacement is zero.
Answer:

Explanation:
let
be the mass attached, let
be the spring constant and let
be the positive damping constant.
-By Newton's second law:

where
is the displacement from equilibrium position. The equation can be transformed into:
shich is the equation of motion.
Answer: ask other people if they like it, or ask what they want to add
Explanation: because maybe other people can can help him improve and brainstorm with other’s.
Answer: 1.88
Explanation
Applying Snell’s Law, sin(1)/sin(2) = n(2)/n(1), where n is the index of refraction and sin 1 and 2 being of incidence and refracted respectively.
1) sin35/sin24 = n(2)/1.33
2) 1.41 = n(2)/1.33
3) n(2) = 1.41 x 1.33
4) n(2) = 1.88
Hope this helps :)