Answer :

Certainly! To find the acceleration due to gravity using the given length and period of a pendulum, we can use the following fundamental equation for the period of a simple pendulum:

[tex]\[ T = 2 \pi \sqrt{\frac{L}{g}} \][/tex]

Where:
- [tex]\( T \)[/tex] is the period of the pendulum (in seconds),
- [tex]\( L \)[/tex] is the length of the pendulum (in centimeters),
- [tex]\( g \)[/tex] is the acceleration due to gravity (in cm/s[tex]\(^2\)[/tex]).

We are given:
[tex]\[ L = 100 \text{ cm} \][/tex]
[tex]\[ T = 0.65 \pi \text{ seconds} \][/tex]

To find [tex]\( g \)[/tex], we need to rearrange the formula to solve for [tex]\( g \)[/tex]:

[tex]\[ T = 2 \pi \sqrt{\frac{L}{g}} \][/tex]

First, isolate [tex]\(\sqrt{\frac{L}{g}}\)[/tex]:

[tex]\[ \frac{T}{2\pi} = \sqrt{\frac{L}{g}} \][/tex]

Next, square both sides to eliminate the square root:

[tex]\[ \left(\frac{T}{2\pi}\right)^2 = \frac{L}{g} \][/tex]

Finally, solve for [tex]\( g \)[/tex]:

[tex]\[ g = \frac{L}{\left(\frac{T}{2\pi}\right)^2} \][/tex]

Now, substitute the given values into the equation:

[tex]\[ T = 0.65 \pi \text{ seconds} \][/tex]
[tex]\[ L = 100 \text{ cm} \][/tex]

Calculate [tex]\(\left(\frac{T}{2\pi}\right)^2\)[/tex]:

[tex]\[ \left(\frac{0.65 \pi}{2 \pi}\right)^2 = \left(\frac{0.65}{2}\right)^2 = \left(0.325\right)^2 \][/tex]

[tex]\[ \left(0.325\right)^2 = 0.105625 \][/tex]

Then, use this result to find [tex]\( g \)[/tex]:

[tex]\[ g = \frac{100}{0.105625} \][/tex]

[tex]\[ g \approx 946.7455621301774 \text{ cm/s}^2 \][/tex]

Therefore, the acceleration due to gravity for the given pendulum length and period is approximately:

[tex]\[ \boxed{946.7455621301774} \text{ cm/s}^2 \][/tex]