Question

The length of second's pendulum is 80cm. What should be the
length, if time period is 1.6 sec?​

Answer 1

Length = 80 cm

Explanation:

Given, length of second's pendulum = 80 cm and time period = 1.6 seconds

∴ Time period, T = 2π $\sqrt{\frac{l}{g} }$

Now , squaring on both sides

$T^{2}$ = 4π ( $\frac{l}{g}$ )

$T^{2}$ ·g = ( 4π² )

T²g / 4π² = l

l = T²g / 4π²

Here ,length = 80 cm, g = 9.8 and π = 3.14

∴ Length = 80 cm