A plane mirror is placed with its plane at an angle 30∘ with the y-axis. Plane of the mirror is perpendicular to the xy-plane and the length of the mirror is 3m. An insect moves along x-axis starting from a distant point, with speed 2 cm/s. The duration of the time for which the insect can see its shown image in the mirror is:

Explanation

To find the location of image, we have to draw a perpendicular on the mirror M from the point O as shown in the figure.

Now from the triangle O' Ao, we have
`sin30^(@)=(OA)/(2)rArrOA=2xxsin30^(@)=1m`
`therefore` Distance of the image from the mirror is AI=OA=1m