Question

simple pendulum of large length is made equal to the radius of the earth.its period of oscillation will be:
1. 84.6 min
2. 59.8 min
3. 42.3 min
4. 21.15 min

Answer 1

T = 2π√(L/g)
R=6.371 × 10^6 m
where R = L

=> T = 2*3.14*√(R/g)

=>T=2*3.14*√(6.371×10^6/10)

=>T=2*3.14 * 798.18

=>T =5,012.6045764652 seconds

=> T= =83.5434096078 mins