This is the angle at which light leaves or bounces off of a surface relative to the normal, or an imaginary line perpendicular to the surface. The law of reflection states that this angle is equal to the angle of incidence.

The angle which the light leaves or bounces off a surface is angle of reflection.

Explanation:

According to laws of reflection we have

Here is the angle of reflection . This is the angle made by the incident ray of light with the normal .

    Normal is the line perpendicular to the surface and passing through the point of contact between incident ray and the surface .

Here is the angle of reflection . This is the angle made by reflected ray with the normal .

second mirror gathers light from a faraway object and reflects it to another mirror. - a.

acceleration = (change in speed) / (time for the change)

change in speed = (20-120)= -100 m/s.

1.5 min = 90 sec

acceleration = -100/90 = -1.11 m/s^2.

we don't care about the 150kg or the 2,500 meters. they don't make any difference.

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