Question

The resultant of two forces $P$ and $q$ is right angle to $P$, the resultant of $P$ and $Q$ acting at the same angle is at right angle to $Q$. Prove that $P$ is the geometric mean of $Q$ and $Q$(i.e. $P=\sqrt{Qq}$ ?

Answer 1

$P=qcos\theta$

$Q=Pcos\theta$

Solving we get $P^2=Qq$

$P=\sqrt{Qq}$