Mon March 21, 2011 By: N Jain

a pendulum is mounted in an elevator that moves down with constant acceleration. how will the the period change??

Expert Reply
Mon March 21, 2011
Dear student,
normally period for pendulum is T = 2π√(L/g)

if we put into elevator and it goes up

then T = 2π√(L/9.8+a)

g = 9.8+a because if elevator goes up and you feel to go down that is why g is bigger. and string tension must support the weight and acceleration upward and also provide restore force, just as if the elevator were at rest in gravity field g = 9.8+a. T will be shorter .
Hope this helps.
Ask the Expert