<span>The line that is drawn perpendicular to the point at which a wave intersects a boundary is know as the Normal .
When the normal is drawn, the incident ray makes an angle with it known as the angle of incidence and the reflected ray makes an angle with it known as the angle of incidence. These angles are always equal.
The refracted ray makes an angle with the normal known as angle of refraction. The sin of angle of incidence to the sin of angle of refraction is called the refractive index( </span>μ= <span>sin i / sin r) .
The formula of the kinetic energy is: where m is a mass of the object, v is speed of the object at the moment of time. So we have: The answer is 2000 Joules.
If the avg speed is 10mi/h and you want to know how long it will take to run 2.5mi/h you put that as a ratio 2.5/10 which is 1/4 of an hour so it will take 15 minutes to run 2.5 miles
