Physics

Problem

Initially, a reflected laser beam emerges along the positive

x

-axis after striking a stationary plane mirror. To steer the beam so that it finally emerges making an angle of

30^{\circ}

above the

x

-axis (within the same plane), through what angle should the mirror be rotated? a)

30^{\circ}

20^{\circ}

15^{\circ}

7.5^{\circ}