Answer:
1. The best definition of refraction is ____.
a. passing through a boundary
b. bouncing off a boundary
c. changing speed at a boundary
d. changing direction when crossing a boundary
Answer: D
Bouncing off a boundary (choice b) is reflection. Refraction involves passing through a boundary (choice a) and changing speed (choice c); however, a light ray can exhibit both of these behaviors without undergoing refraction (for instance, if it approaches the boundary along the normal). Refraction of light must involve a change in direction; the path must be altered at the boundary.
D. Yield signs is the answer
Answer:
1.18 sec
Explanation:
v = 0
u = 3.25m/s
v = u - gt
t1 = u/g = 3.25/9.8 = 0.332 s
height above board = v²/2g =
3.25²/(2×9.8) = 0.54 m
time to fall from there to water
t2 = √(2h/g) = √(2(3+ 0.54)/9.8) = 0.85 s
total time = t1 + t2
total time = 0.85 + 0.332 = 1.182 s
