Question

If the length of the simple pendulum is increased by 69 %, then the %increase in its time is?

Answer 1

T = 2π √l/g

69% increases means L= 169 ,if initial L is 100

So, T = 2π √100/g

T' = 2π √169 /g

T/T' = 2π √100/g / 2π √169 /g

T/T' = 10/13

Change in time period = T' - T÷ T x 100

= 13 -10 ÷ 10 x 100

= 30%