Originally Posted by

**Ultros88** Trying to figure this out. I know it relates to the fact that an inscribed angle subtended by a diameter is a right angle, but I can't put the answer into appropriate mathematical language:

An objects slides down an inclined plane OP' starting from rest at O, which is the top of a circle of diameter OP, where P and P' lie in a horizontal line. Show that the point Q reached in the time, t, required to fall straight down from O to P lies on a circle with OP as diameter.

Thanks.