Because a larger angle will exacerbate the dampening effect. The dampening effect is an effect that tends to reduce the amplitude of any oscillations.
http://en.wikipedia.org/wiki/Damping
It is preferable to keep the amplitude of a simple pendulum small because larger amplitudes can lead to nonlinear behavior and make the system harder to analyze. Keeping the amplitude small ensures that the motion remains approximately harmonic, simplifying calculations and predictions.
The motion of the simple pendulum will be in simple harmonic if it is in oscillation.
Small: This is to ensure that the motion of the pendulum mostly stays along one direction, i.e. it is swinging back and forth as opposed to rotating or moving erratically. Only when the pendulum is moving in this manner can you say that it follows SHM - Simple Harmonic Motion (If that is the aim of the experiment)
The time period of a simple pendulum is not affected by the mass of the bob, as long as the amplitude of the swing remains small. So, doubling the mass of the bob will not change the time period of the pendulum.
The ideal model of a simple pendulum assumes the pendulum mass is concentrated at a single point, the string or rod is massless and frictionless, and the pendulum moves in a vacuum with no air resistance. Additionally, it assumes small amplitude oscillations, and the only force acting on the pendulum is gravity.
It is preferable to keep the amplitude of a simple pendulum small because larger amplitudes can lead to nonlinear behavior and make the system harder to analyze. Keeping the amplitude small ensures that the motion remains approximately harmonic, simplifying calculations and predictions.
The motion of the simple pendulum will be in simple harmonic if it is in oscillation.
Small: This is to ensure that the motion of the pendulum mostly stays along one direction, i.e. it is swinging back and forth as opposed to rotating or moving erratically. Only when the pendulum is moving in this manner can you say that it follows SHM - Simple Harmonic Motion (If that is the aim of the experiment)
The time period of a simple pendulum is not affected by the mass of the bob, as long as the amplitude of the swing remains small. So, doubling the mass of the bob will not change the time period of the pendulum.
wind resistance cannot be ignored in considering a simple pendulum. The wind resistance will be proportional to a higher power of the velocity of the pendulum. A small arc of the pendulum will lessen this effect. You could demonstrate this effect for yourself. A piece of paper attached to the pendulum will add to the wind resistance, and you can measure the period both with and without the paper.
The ideal model of a simple pendulum assumes the pendulum mass is concentrated at a single point, the string or rod is massless and frictionless, and the pendulum moves in a vacuum with no air resistance. Additionally, it assumes small amplitude oscillations, and the only force acting on the pendulum is gravity.
Assuming an idealised pendulum with a small amplitude, both are examples of simple harmonic motion. That is, the second derivative of the curve is directly proportional to its displacement but in the opposite direction. If the amplitude (swing) of the pendulum is large or if the majority of its mass is not oi the "blob" the relationship is only approximate.
A pendulum oscillating with a larger amplitude has a longer period than a pendulum oscillating with a smaller amplitude. This is due to the restoring force of gravity that acts on the pendulum, causing it to take longer to swing back and forth with larger swings.
When finding the time period of a simple pendulum, ensure that the amplitude of the swing is small, as larger amplitudes can introduce errors in the calculation. Make sure the pendulum is released from rest each time and avoid air resistance by conducting the experiment in a vacuum or minimizing the effects of air resistance as much as possible. Triple-check the length of the pendulum and measure it accurately to get precise results.
The change of amplitude affects the time of one cycle of a pendulum if the amplitude is big. In such a case, time increases as amplitude increases. In the case of a small amplitude, the time is very slightly affected by amplitude and is considered negligible.
A simple harmonic motion is one for which the acceleration of the body into consideration is proportional its displacement from the mean position and the direction of the acceleration is always directed towards that mean position. It can be shown that, provided that the amplitude of oscillation is small, the motion of a simple pendulum is simple harmonic. All simple harmonic motions follow one rule F=-kx . When the oscillation is small(around 5 °), the motion of simple pendulum is simple harmonic motion.
Keeping the amplitude of the swinging pendulum small is important to maintain the regularity and predictability of its motion. Large amplitudes can introduce non-linearities that impact the period of oscillation and make the pendulum less reliable for timekeeping or measurement purposes. Additionally, larger amplitudes can result in higher energy loss due to air resistance or friction, leading to dampening of the pendulum's motion.