Explanation :
Static friction is the frictional force between two objects that are at rest. While sliding friction is the frictional force between two objects in contact and are sliding w.r.t each other.
Static friction is usually greater than sliding friction because in static friction the contact forces is more and the interlocking between objects is tight as compared to sliding friction.
Answer:
a) 3.33 ns
b) Water distance = 0.75 m
Glass distance = 0.66 m
Diamond distance = 0.41 m
Explanation:
We take the speed of light, c = m/s.
Speed = distance/time
Time = distance/speed
a)

t = 3.33 ns
b)
Refractive index, n = speed of light in vacuum / speed of light in medium





Thus, the distance traveled in the same time is numerically equal to the reciprocal of the refractive index.
For water n = 1.333
d = 1/1.333 = 0.75 m
For glass n = 1.517
d = 0.66 m
For diamond n = 2.417
d = 0.41 m
If the +12V is on one side of the 2.5 ohm R then.............
V = (2.5/8) x 12 otherwise......
V = (5.5/8) x 12
The runner has initial velocity vector

and acceleration vector

so that her velocity at time
is

She runs directly east when the vertical component of
is 0:

It's not clear what you're supposed to find at this particular time... possibly her position vector? In that case, assuming she starts at the origin, her position at time
would be

so that after 10.4 s, her position would be

which is 19.9 m away from her starting position.
I believe it’s all of the questions