Question

A simple pendulum is suspended from the roof of a train. If the train is moving with an acceleration of 49 cm/s² , then the angle of inclination of the string about the vertical will be ____.

 a) 20°  

 b) 0°   

 c) 30°

 d) 3°

Answer 1

pseudo force=ma

gravity=mg

tan\(\theta = {ma\over mg }\)

\(\theta = tan^{-1}({ma\over mg})\)

\(=tan^{-1}({ 0.49\over 9.8})\)

\(=tan^{-1}(0.05)\)

=\(3 ^o\)