Measuring Simple Pendulum Acceleration: Tips for Accuracy and Reliability

In summary, the conversation discusses using a simple pendulum to practice measuring the acceleration due to gravity. The process involves assembling a clamp, boss head, and resort stand, attaching a string and a bob, and measuring the time for the pendulum to complete a period. The information collected can then be used to calculate the acceleration due to gravity using the formula g = 4π2l/T2. There are two types of error to consider, including errors from not replicating ideal conditions and propagation of errors when measuring the length and time. It is important to minimize errors by considering factors such as air resistance and ensuring all mass is at the proper distance. Additionally, it is important to accurately measure time as it is squared in the formula
  • #1
chopstick
16
0
For a simple pendulum practice with clamp, boss head and resort stand assembled, also a string attached to the end of clamp and a bob, then swings it and measure the time for it to complete a period.

At the end use the information collected to calculate acceleration due to the gravity by the formula g = 4π2l/T2.

What could the accuracy and reliability be effected? (Equipments, angles or the error should avoid) And what kind of string or bob will most suit? Why?
 
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  • #2
Welcome to PF.
For HW questions you have to make some sort of attempt before we can help.

To get you started, if a quantity is squared would that make any error in that quantity worse or better?
 
  • #3
mgb_phys said:
Welcome to PF.
For HW questions you have to make some sort of attempt before we can help.

To get you started, if a quantity is squared would that make any error in that quantity worse or better?

i think that will make it worse. so i measured the period for it complete ten oscillations and repeat it with different length of strings, due that both of them are the only variables in the equation. Even L and T are the only variables, but the angle should some how involved, would it?

and also for the string and 'bob', only thing i can think of was the air resistance, anything else that i should think about?

sorry for didn't show enough effort, i thought that could make the question simple. i just something else that can increase the accuracy and reliability in that practise. just looking for some hint
 
Last edited:
  • #4
There are two types of error to consider .

1, You are trying to use an ideal law for the period - no friction, all the weight acts at L etc.
So you want your experiment to be as close to the imaginary ideal as possible and reduce effects like.
Air friction on the string (do you want a big swing or small ?)
All the mass to be at distance L (so the string must be much lighter than the bob)
No friction where the string pivots.

2, There is also propagation of errors - which is what I hinted at.
The answer is proportional to L so an error in L will give the same percentage error in 'g'
But 't' is squared so an error in 't'gives a bigger error in 'g' - so you have to put more effort into measuring 't' accurately than you do into measuring 'L'
 
  • #5
thank you for your help, i been confuse for whiles.
 
  • #6
What if you square a quantity between -1 and 1? Doesn't the error decrease?
 
  • #7
damn! i cannot understand it, what does between -1 and 1 mean
 

1. What is a simple pendulum?

A simple pendulum is a device that consists of a mass attached to a fixed point by a string, wire, or rod. It is used to demonstrate the concept of harmonic motion and can also be used to measure time and acceleration due to gravity.

2. How does a simple pendulum accelerate?

A simple pendulum accelerates because of the force of gravity acting on the mass. As the mass moves away from its resting position, it experiences a restoring force that pulls it back towards its equilibrium point. This back-and-forth motion results in an acceleration towards the center of the arc.

3. How is the acceleration of a simple pendulum calculated?

The acceleration of a simple pendulum can be calculated using the formula a = -g * sin(theta), where "a" is the acceleration, "g" is the acceleration due to gravity (9.8 m/s^2), and "theta" is the angle that the pendulum makes with the vertical axis.

4. Does the mass of a simple pendulum affect its acceleration?

No, the mass of a simple pendulum does not affect its acceleration. The acceleration is solely determined by the length of the string and the angle at which it is released. However, the mass does affect the period of the pendulum, which is the time it takes for the pendulum to complete one full swing.

5. What factors can affect the acceleration of a simple pendulum?

The acceleration of a simple pendulum can be affected by the length of the string, the angle at which it is released, and the acceleration due to gravity. Other factors such as air resistance and friction can also affect the acceleration, but they are typically negligible in simple pendulum experiments.

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