Question

In the figure given below an ideal pendulum oscillates in vacuum between two extreme positions a and b . If it goes from position b to mean position c in 3s then it will complete 3.5 oscillation in .

Answer 1

0.5oscillation =3s
then 3.5 =7 times 0.5
then 3 x 7=21
therefore 21s are taken.

Answer 2

According to the given details, we can consider that an ideal pendulum oscillates in vacuum between two extreme positions a and b.

If it goes from position b to mean position c in 3s then it will complete 3.5 oscillations in s seconds.

The calculation is given below:

3s = 0.5oscillation

Then 3.5 =7 times 0.5

Hence 21s are taken