(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A mirror is moving to the right with a velocity 15 m/s, and an object is moving to the right with a speed of 5m/s. All speeds are wrt ground. Find the velocity of image wrt ground.

2. Relevant equations

3. The attempt at a solution

I present to you two probable solutions:

1) Using formula: V_{IMAGE}=2V_{MIRROR}-V_{OBJECT}

Now, its a mere substitution problem. Using right as positive direction, we get the required velocity as 25m/s to the right.

2) This is a controversial one. I thought about this as i like to explore all the different correct of incorrect methods of a problem.

the above problem is equivalent to: the mirror is moving to the right with a velocity of 10m/s and the object is at rest. Now, substituting in the formula used in the previous method, V_{IMAGE}=20m/s to the right.

Now, my book says that that the correct answer is 10m/s, but its not matching with any of my answers. Please check it and let me know why both are incorrect.

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# Velocity of image in plane mirror

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