Question

A simple pendulum is suspended from the roof of a trolley which moves in a horizontal direction with an acceleration a, then the time period is given by T=2π√(l/g), where g is equal to ___________

(a) g

(b) g-a

(c) g+a

(d) √(g^2+a^2 )

I had been asked this question in an international level competition.

The query is from Wave Motion topic in division Waves of Engineering Physics I

Answer 1

Right choice is (d) √(g^2+a^2 )

Easiest explanation: As g and a are acting along perpendicular directions, the effective value of acceleration due to gravity is

g^‘=√(g^2+a^2).