A point object moves towards a concave mirror with a speed $10 c m s^{- 1}$ along the principal axis. The magnitude of the velocity of object with respect to image when the object is at distance of 15cm from the pole is __ $c m s^{- 1}$ . (Focal length of the mirror kept at rest is 10cm )

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Raj Pandey | Contributor-Level 9

3 weeks ago

$v = \frac{f u}{u - f} = \frac{(- 10) (- 15)}{- 15 + 10} c m = - 30 c m$

$v_{image} = \frac{d v}{d t} = - {(\frac{v}{u})}^{2} \frac{d u}{d t} = - {(\frac{- 30}{- 15})}^{2} (10) c m s^{- 1} = - 40 c m s^{- 1}$

$V_{object} = \frac{d u}{d t} = + 10 c m s^{- 1}$

Relative velocity $= v_{object} - v_{image}$

$= 10 - (- 40) = 50 c m s^{- 1}$

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A point object moves towards a concave mirror with a speed $10 c m s^{- 1}$ along the principal axis. The magnitude of the velocity of object with respect to image when the object is at distance of 15cm from the pole is __ $c m s^{- 1}$ . (Focal length of the mirror kept at rest is 10cm )

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A point object moves towards a concave mirror with a speed 10 c m s - 1 along the principal axis. The magnitude of the velocity of object with respect to image when the object is at distance of 15cm from the pole is __ c m s - 1 . (Focal length of the mirror kept at rest is 10cm )

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A point object moves towards a concave mirror with a speed $10 c m s^{- 1}$ along the principal axis. The magnitude of the velocity of object with respect to image when the object is at distance of 15cm from the pole is __ $c m s^{- 1}$ . (Focal length of the mirror kept at rest is 10cm )