Explanation:
It is given that,
Time period of the pendulum, T = 26.5 s
1. The time period of the pendulum is given by :
[tex]T=2\pi \sqrt{\dfrac{l}{g}}[/tex], l is the length of the pendulum
[tex]l=\dfrac{T^2g}{4\pi ^2}[/tex]
[tex]l=\dfrac{(26.5)^2\times 9.8}{4\pi ^2}[/tex]
l = 174.32 meters
2. On the surface of moon, the acceleration due to gravity, [tex]g'=1.67\ m/s^2[/tex]
Time period is given by :
[tex]T=2\pi \sqrt{\dfrac{174.32\ m}{1.67\ m/s^2}}[/tex]
T = 64.19 seconds
Hence, this is the required solution.