An object approaches a stationary plane mirror normally at 5 m/s. What are the speed of its image relative to the mirror and the rate at which object-image separation decreases?
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An object approaches a stationary plane mirror normally at 5 m/s. What are the speed of its image relative to the mirror and the rate at which object-image separation decreases?

G1 Physics · Accepted Answer

For a stationary mirror, the image has equal and opposite normal velocity. Thus its speed relative to the mirror is 5 m/s and object-image separation decreases at 5+5=10 m/s.