Question

Please help on related rates i do not get it

A light is fastened on a rolling cart 1m above the floor. The light moves at 2m/s towards a 2m tall man standing 4m from a wall. How fast is the tip of the mans shadown on the wall moving when the light is 7m from the wall?

Answer 1

@phi

Answer 2

This resource will help you with these kinds of problems: http://www.intmath.com/applications-differentiation/4-related-rates.php.
Generally the first step with these kinds of problems is to simply draw a picture. In this case the picture will look something like this: