At an instant, a concave mirror has |v/u|=2. The object approaches the mirror at 3 cm/s relative to the mirror. Find image speed relative to the mirror in cm/s.
Physics · Geometrical optics · spherical mirror
JEE Mains NEET

Question

At an instant, a concave mirror has |v/u|=2. The object approaches the mirror at 3 cm/s relative to the mirror. Find image speed relative to the mirror in cm/s.

G1 Physics · Accepted Answer

Axial speed amplification magnitude is |v/u|²=4, so 4×3=12 cm/s.