College

The period [tex]T[/tex] (in seconds) of a pendulum is given by [tex]T=2 \pi \sqrt{\frac{L}{32}}[/tex], where [tex]L[/tex] stands for the length (in feet) of the pendulum. If [tex]\pi=3.14[/tex] and the period is 1.57 seconds, what is the length?

A. 2 feet
B. 8 feet
C. 16 feet
D. 20 feet

Answer :

Sure! Let's go through the solution to find the length of the pendulum step-by-step:

We are given the formula for the period [tex]\( T \)[/tex] of a pendulum:

[tex]\[ T = 2 \pi \sqrt{\frac{L}{32}} \][/tex]

where:
- [tex]\( T \)[/tex] is the period of the pendulum in seconds.
- [tex]\( L \)[/tex] is the length of the pendulum in feet.
- [tex]\( \pi \)[/tex] is approximately 3.14.
- The constant 32 is the acceleration due to gravity measured in feet per second squared.

We are told that the period [tex]\( T \)[/tex] is 1.57 seconds, and we need to find the length [tex]\( L \)[/tex].

### Steps to Find [tex]\( L \)[/tex]:

1. Start with the given formula:

[tex]\[ T = 2 \pi \sqrt{\frac{L}{32}} \][/tex]

2. Plug in the given values:

[tex]\[ 1.57 = 2 \times 3.14 \times \sqrt{\frac{L}{32}} \][/tex]

3. Solve for [tex]\( \sqrt{\frac{L}{32}} \)[/tex]:

Divide both sides by [tex]\( 2 \times 3.14 \)[/tex]:

[tex]\[ \frac{1.57}{2 \times 3.14} = \sqrt{\frac{L}{32}} \][/tex]

4. Square both sides to eliminate the square root:

[tex]\[ \left(\frac{1.57}{2 \times 3.14}\right)^2 = \frac{L}{32} \][/tex]

5. Solve for [tex]\( L \)[/tex]:

Multiply both sides by 32:

[tex]\[ L = 32 \times \left(\frac{1.57}{2 \times 3.14}\right)^2 \][/tex]

After calculating this expression, we find that [tex]\( L \)[/tex] is 2 feet.

So, the length of the pendulum is 2 feet.