Hi
How do I do this:
A lamp is 40 m above the ground and a stone is dropped from the same height at a point 10 m away. Find the speed of the shadow on the ground given that in t seconds the stone falls m.
Thanks a lot!
Hello SunyataStudy the diagram I have attached. The distance m represents the distance of the shadow from , the point directly below , where the stone was dropped.
Using similar triangles:What you need to do now:
Substitute into this equation the values I've given you in the diagram.Can you complete this now?
Solve for in terms of .
Differentiate to find . This represents the speed of the shadow.
Grandad