Car B overtakes another car A at a relative speed of 40 m s⁻¹. How fast will the image of car B appear to move in the mirror of focal length 10 cm fitted in car A, when the car B is 1.9 m away from the car A?
Options

Question

Car B overtakes another car A at a relative speed of 40 m s⁻¹. How fast will the image of car B appear to move in the mirror of focal length 10 cm fitted in car A, when the car B is 1.9 m away from the car A?

Options

G1 Physics · Accepted Answer

Derived solution: Step 1: Use the spherical-mirror relation 1/f = 1/v + 1/u with m = - v/u and R = 2f, following the Cartesian sign convention. Step 2: Substitute the values given in the question and apply the geometry/sign convention shown. Step 3: On simplification the result is 0.1 m s⁻¹. Therefore the correct option is D.