A convex lens of focal length 10 cm and a concave lens of same focal length in value are placed co-axially at a separation of 20 cm as shown in figure. A point object is at infinity on the principal axis. Take the optic center of convex lens as origin of co ordinate system and the principal axis as x-axis as shown in figure.

In the initial positin (as given in the passage ) if the concave lens has a velocit of 9 cm/s towards the convex lens, the velocity of the final image will be

Options

A. 10 cm/s along positive x-axis
B. 6.75 cm/s along negative x-axis
C. 8 cm/s along negative x-axis
D. 8 cm/s along positive x-axis

Answer

B