Question

A point object on the principal axis at a distance 15 cm in front of a concave mirror of radius of curvature 20 cm has velocity 2 mm/s perpendicular to the principal axis. The velocity of image at that instant will be

Answer 1

Explanation:

Transverse magnification = mT = - v/u Longitudinal magnification = mL = - dv/du = m2T here : du = 2mm; u = 15 cm; f = 10 cm; dv = ? ⇒ dv = 8 mm ∴ Amplitude of image oscillation is 8 mm.