An ant is 15 cm from the convex mirror of focal length 10 cm. if the ant starts to move towards the mirror with 0.5 m/s. calculate the velocity of the image.

Magnitude of the velocity of image is 2 m/s

Explanation:

As we know that the mirror's formula for convex lens,

Given that the ant is 15 cm from the convex mirror,

And focal length of the mirror is,

And the ant is moving towards the mirror,

Now calculate v,

Now differentiate the mirror's formula with respect to t and in this focal length is constant.

Now put all the variables to get velocity of image,

Therefore, the velocity of image is -2 m/s negative sign means that the direction of velocity of image is opposite to direction of velocity of ant.

the answer is 3.1 his answer is wrong mines is right

no. dot product   =0 when vecs at right angles