Answer:
(a) 1.5 second
(b) 0.56 m
Step-by-step explanation:
Pendulum makes 120 oscillations in 3 min that means in 180 seconds
time taken by the pendulum to complete one oscillation is called time period.
(a) So, the time period is 180 / 120 = 1.5 second
T = 1.5 second
Thus, the time period of the pendulum is 1.5 second.
(b) g = 9.8 m/s^2
The formula for the time period is given by
![T =2\pi \sqrt{(L)/(g)}](https://img.qammunity.org/2020/formulas/physics/college/glm4govqutudavz7btjc4hxhwpiivyf069.png)
Where, L be the length of pendulum
![1.5 =2* 3.14 \sqrt{(L)/(9.8)}](https://img.qammunity.org/2020/formulas/physics/college/t80162rp6fg29ei3vhzbeu1mk4g5vrgasl.png)
![0.057= {(L)/(9.8)}](https://img.qammunity.org/2020/formulas/physics/college/fru5fajfbhcuq4o2yf2r95y02rn3em5h0r.png)
L = 0.56 m
Thus, the length of the pendulum is 0.56 m .