Do your data confirm this expectation? You either have to calculate it using all points e. You should position the additional masses nearer to the center of the glider, to distribute the weight evenly on all sides of the glider. There are many variables one could look into, such as displacement, angle, damping, mass of the bob etc. And try thinking a bit yourself and do not blindly copy answers from somewhere else. Crawford, Waves, Berkeley Physics Series New York: McGraw-Hill, 1968 , v.
Therefore, the oscillatory behavior of a real physical system disappears after a certain time interval. A point that should be emphasized is that this kind of experiment allows showing students that some variables that characterize a real physical system depend on the size of the system under consideration. The slope of the line in the graph of T² against L can be used to determine the gravity of the pendulum motion. What sources of error might you be neglecting or underestimating in this part of the lab? Then make the angle of release 20º and do three trials again. On the other side of the glider, the springs stretch enough so that the restoring force equals out the string tension on the other side, until the net force is 0, and the glider stops. The period remained nearly the same throughout every trial, which was to be expected. Then, you should verify that the initial spring potential energy of the system equation 5 was fully converted into the final kinetic energy of the system equation 6.
Krane, Physics for Students in Science and Engineering New York:Wiley, 1992. The functional relationship between the variables in is given by where by the substitution of Eq. Palavras-chave: sistema massa-mola, lei de Hooke, constante elástica, movimento harmônico simples, amortecimento. Figure 7 : Experimental set-up for a simple pendulum If the bob is moved away from the rest position through some angle of displacement θ as in Fig. In agreement with that result, it is possible to calculate the spring's elastic constant k through the ratio Eq.
The black points in the oscillation correspond to the experimental values and the solid curve to the theoretical fit obtained by means of Eq. For the foregoing reasons, this experimental study is an excellent one for general physics courses. The next part, you will determine the period, T, of oscillation caused by two springs attached to either side of a sliding mass. With a 2-meter stick, carefully measure the length of the string, including the length of the pendulum bob. The tension force of the string is balanced by the component of the gravitational force that is in line with the string i.
Rino, Revista Brasileira de Ensino de Física 28, 195 2006. After testing the affect of change in the angle of release you can start testing the effect of change when you change the. Add one-third this mass to the oscillating mass before calculating the period of oscillation. This was repeated with various amounts of mass. Though the air track reduces friction significantly, it does not remove it entirely, so some damping of the motion will occur. It is important to note that the ω , k, and γ variables shown in have all been determined experimentally, and show a linear correlation coefficient of adjustment between them of 0.
Although we could use equation 4 above describe the total energy as the sum of the kinetic and potential energies at any given time, we will simplify our analysis by choosing an initial point and a final point with only one type of energy each. The amplitude will decreases with time since the energy will losses. This should convince you that using equation 9 , which neglects the spring masses, is adequate for estimating the period of the oscillatory motion. It was Galileo who first observed that the time a pendulum takes to swing back and forth through small distances depends only on the length of the pendulum The time of this to and fro motion, called the period, does not depend on the mass of the pendulum or on the size of the arc through which it swings. Note that the damping factor γ given by Eq. In this endeavor, the spring constant was valued at 3. Damping always occurs when there is.
The motion of a child on a swing can be approximated to be sinusoidal and can therefore be considered as simple harmonic motion. I took the highlighter and put it on the table beside the ring stand so I can control my angle every time I swing the string that has the plasticine at its end. It follows then that a long pendulum has a greater period than a shorter pendulum. String A metre ruler was used to determine the length of the string. Do this two more times so you have three trials for the release angle of 10º.
The length L of the simple pendulum is measured from the point of suspension of the string to the center of the bob as shown in Fig. For its uncertainty, you may assume that the photogate is precise so that there is no uncertainty in the time of the glider passing through the photogate beam. It can be reduced by using rhythm to count before started. If energy is conserved, these values should be equal. In this paper we will show the difference obtained in determining the frequency of oscillations according to theoretical models defined by Eqs.
This behavior is due to the fact that the springs that have a higher damping factor have a higher elastic constant k, and therefore oscillate with higher angular frequency. Using a tape measure, the measurement of the elongation Δ x experienced by the spring was carried out when masses m were suspended at its free end see. The period of a pendulum is also known as the time taken for the pendulum oscillates one complete cycle. After the required measurements, one experiment was carried out to find the Figure 1: Diagram of the set-up for this experiment degree of damping in our set-up. Controlled variable: Mass of the plasticine.