100 the law of reflection states that the angle of incidence equals the angle of reflection. define the angle of incidence in terms of a line normal to the surface.

A line that's 'normal' to the surface is perpendicular to the surface.

The angle of incidence is the angle between the normal and the light ray ARRIVING at the surface.

The angle of reflection is the angle between the normal and the light ray LEAVING the surface after it's reflected.

The law of reflection says these two angles are equal.

false br

f=ma newton

f=100x2.5=250n