design an experiment to verify that T is derctly proportional to sqare toot of lenght of the pendulam. (pendulam investigation)

Try timing the period with different masses on the end of a string. Graph the results on log paper if you have it. If not then graph square of the period versus the length and see if you get a straight line no matter how big the mass may be.

how do we prove dats T is directly proportional to square root of the length of pendulam?

You can either perform the experiment that Damon has described, or derive the proof using Newton's law and mathematics, by solving the time-dependent differential equation of motion.

The approximation sin x = x is usually made when deriving

T = 2 pi sqrt(L/g)

where x is the amplitude of oscillation

Without the sin x = x approximation, there is an additional amplitude-dependent coefficient (which equals 1 for small angles of oscillation), but the period remains independent of mass.

To design an experiment to verify the relationship between the period (T) of a pendulum and the square root of its length, you can follow these steps:

1. Gather materials: Obtain a pendulum (e.g., a weight attached to a string or rod), a stopwatch or timer, a ruler or measuring tape, and a lab notebook to record your observations.

2. Define the variables: In this experiment, the independent variable is the length of the pendulum (L), and the dependent variable is the period (T) of the pendulum. Keep all other variables constant (e.g., mass, amplitude, angle of release) to ensure accurate results.

3. Set up the experiment: Attach the weight to the string or rod, making sure it is securely fastened. Measure the length of the pendulum using the ruler or measuring tape and record it in your lab notebook.

4. Determine the period: Start the stopwatch or timer and release the pendulum from a small angle (ensure you release it consistently each time). Measure the time it takes for the pendulum to complete a full swing or back-and-forth motion (from one extreme to the other) using the stopwatch or timer. Record the period in your lab notebook.

5. Repeat the measurements: Repeat step 4 for various lengths of the pendulum. You can change the length by adjusting the string or rod while keeping the other variables constant. Ensure you take multiple readings for each length to minimize errors and calculate an average period for each length.

6. Analyze the data: Plot a graph with the period (T) on the y-axis and the square root of the length (sqrt(L)) on the x-axis.

7. Determine the relationship: If the relationship between T and sqrt(L) is directly proportional, the graph should be a straight line passing through the origin. You can perform a linear regression analysis on the data points to determine the equation of the line and its correlation coefficient.

8. Draw conclusions: Based on the analysis, if the correlation coefficient is close to 1 and the equation of the line has a positive slope, it confirms that the period (T) is directly proportional to the square root of the length (sqrt(L)) of the pendulum.

Remember to repeat the experiment multiple times with different lengths to ensure accuracy and precision. Additionally, always adhere to safety precautions while working with a pendulum and any other equipment.