Answer:
Step-by-step explanation:
Expression for time period of pendulum is given as follows
![T=2\pi\sqrt{(l)/(g) }](https://img.qammunity.org/2021/formulas/physics/middle-school/k46hc5lmwalt0pkn771mx0h9aoczabsb6b.png)
where l is length of pendulum and g is acceleration due to gravity .
Putting the given values for first place
![2.67=2\pi\sqrt{(l)/(9.77) }](https://img.qammunity.org/2021/formulas/physics/college/vi2cn90bmkvw6tdp0ay09cm1mhcxea85ap.png)
Putting the values for second place
![T=2\pi\sqrt{(l)/(9.81) }](https://img.qammunity.org/2021/formulas/physics/college/7buuobaes1n7v7bm65e6rm9fgk2m28rkgl.png)
Dividing these two equation
![(T)/(2.67) =\sqrt{(9.77)/(9.81) }](https://img.qammunity.org/2021/formulas/physics/college/1hlal3g7uwt8t5aqrgismnylyr1mafaq3g.png)
T = 2.66455 s.