Answer
The refracted wave must obey Snell's equation
Ni sin θi = Nr sin θr
If Nr differs from Ni then sin θr will differ from sin θi
If the wave originates from point A and ends at point B then Snell's Law shows that the time for light to get from point A to point B is a minimum.
Answer:
The angular displacement is 
Explanation:
From the question we are told that
The initial angular speed is 
The angular acceleration is 
The time take is 
Generally the angular displacement is mathematically represented as

substituting values


Answer:
Explanation:
We are not told where A and B are, but I'll assume that they are two points on the orbit of earth about the sun.
As that orbit is an ellipse, the two points likely do not have the same distance between the earth and sun.
As gravity varies with the inverse of the square of the distance (F = GMm/d²), the force at the closer distance will be greater than the force at the longer distance.
Answer:
What is the difference between muscular strength and muscular endurance? Muscular strength is a measure of how much force you can exert in one repetition. Muscular endurance refers to the ability to perform a specific muscular action for a prolonged period of time.
Explanation:
Answer:
D) 11 m/s
Explanation:
We have to calculate the velocity of the hot dog with respect to the observer still outside the train. This velocity will be given by:

where
is the velocity of the train (towards right)
is the velocity of the man (towards right)
is the velocity of the hot-dog (towards left, so we put a negative sign)
By replacing the numbers into the equation, we find

and the positive sign means the velocity is toward right.