A plane mirror moves normally toward a stationary object with speed u. What is the speed of the image relative to the ground?
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A plane mirror moves normally toward a stationary object with speed u. What is the speed of the image relative to the ground?

G1 Physics · Accepted Answer

For normal coordinates, xᵢ=2xₘ−xₒ. With stationary object, vᵢ=2vₘ, so the image speed is 2u.