La Ciencia Entre Nosotros

FUN WITH A SIMPLE PENDULUM
By Dr. Muhammad Bhatti- University of Texas Pan American


Purpose:
To determine the important constant acceleration of gravity of the Planet Earth

Materials:Calculator, mass, meter stick, string (thread), stand, protractor, stopwatch

Procedure:
1. Attach the mass to one end of a meter long string and the other end to the horizontal rod.
2. Adjustthe string about .75 m and pull the mass on one side about 10 degree from the equilibrium position and release it. It will start swinging on both sides at equal distance. Observe the motion of thependulum. See if it’s a repetitive motion.
3. Measure with a stopwatch that how long (in seconds) it took to complete 10 swings (oscillations)? Record in the table below.
4. Calculate how long (inseconds) it took to complete one period (T). The period is equal to the total time for 10 swings divided by the number of 10 complete swings. Record in the table.
5. Repeat the process two moretimes, with different string length. Use a different mass to repeat all the process.
6. Determine the gravity using the formula: g= 4π2 L
T2|String |Time for |Time for one |Gravity of the Planet Earth |
|Length (L) m |10 swings |complete swing |g= 4π2 L |
| |t (s)|T (s) |T2 |
| | | |T2 |
| | || |
| | | | |
| | | ||
| | | | |


Conclusion and Questions:
- Do you get value g close to 9.71 – 9.72...