If a laser beam is shot straight up from the bottom of a pool so that it intersects the pools surface in a perpendicular fashion, what will the angle of refraction be in the air?
a) 0
b)45
c)90
d)this cannot ve measured

A. the change in medium cannot affect the angle if the angle is perpendicular.

its a 5.5 n

glad that

the minimum constant speed at which she can catch the train is 2.7 m/s

given:

acceleration = 0.6

time = 4.5 s

to find:

velocity = ?

formula used:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

solution:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

v = 0 + (0.6 × 4.5)

v = 2.7 m/s

the minimum constant speed at which she can catch the train is 2.7 m/s