Order of work

Exercise 1: Determination of the gravitational acceleration using a working pendulum

        1. Get acquainted with the design of a universal pendulum MTF-04.

2. Strengthen the goods and in the extreme division of the scale (2 cm.) From the prism G (see. Fig. 3.2.) And hang the pendulum of this prism.

        3. Turn on the power meter cord to the mains supply.

        4. Press the switch "Network", checking whether all indicators show the meter number zero, and if the photoelectric sensor light is on.

       5. Reject the pendulum from the equilibrium position at an angle of no more than 5 degrees (the upper end of the rod must be free to counter cross beam sensor) and press "Reset" after the 3-5 full swing.

       6. Press "Stop" After counting meter periods of 19 complete oscillations (instrument reading stops at 20).

       7. Determine the working period of the pendulum by the formula:

(3.22)

where t-time measured millisekundomerom 20 complete oscillations.

      8. To remove the pendulum and set it on the prism О^/.

      9. On this prism to repeat the experience of claims. 5-7.

    10. Move the goods A 1 cm (one division on the web), and repeat the experiment Nos. 5-9.

    11. Repeat the 5-10 experience for the division of the rod (6-7 cm).

    12. plotted oscillation period T by dividing the rod d (cm), corresponding to the position of cargo A. Find the intersection point of the curves, which corresponds to the position of the load A with the closest match at the swing periods with respect to both poles. The measurement results are recorded in Table 5.1.

Table 5.1

n	d, cм	Swing on the O		Swing on the O /
		t, c	T, c	t, c	T, c

8. Secure the load And found via the chart position. Find and distance. To do this, put the pendulum horizontally on a special supporting prism and achieve its equilibrium. Mark the balance point and measure the desired distance and (see para. 5.3.).

9. suspending the pendulum in one and the other prism (without changing the load position), to determine the appropriate periods of vibration Т₁ and Т₂ . Each period to determine at least 3 times and 50 complete oscillations.

10. Calculate the formula (3.19) is the acceleration of gravity. In this formula, Т₁ and Т₂ have mean values ​​of three measurements, respectively.

11. Calculate the ratio (3.21.) Measurement error. To determine the need to use the standard error of a certain reliability , ie

(3.23.)

where -the coefficient of the Student; the mean square error is equal to (3.24).

     

(3.24.)

 12. The results of measurements and calculations recorded in Table 3.2.

                                                                         

Table 3.2.

n	d, cм			Swing on the O			Swing on the O /		м/с2
				t1,c	T1,c	T1,c	t2 ,c	T2, c

Exercise 2: Defining the free fall with the help of a mathematical pendulum

1. Turn the upper bracket for 1800.

2. Install the lower bracket with a photoelectric sensor at a distance (the length of the distance between the prisms О and О^/ defined in Exercise 1).

3. Turn the screw on the top bracket to establish the mathematical pendulum length, with hell on the ball must be at the level of the body features of the photoelectric sensor.

4. Enter a mathematical pendulum in motion, the ball deflecting no more than 50 from the equilibrium position.

5. Press the "Reset" button.

6. After calculating the 19 meter fluctuations press "Stop" (Reading the meter stops at 20).

7. According to the formula (3.22) to determine the period of oscillation of the mathematical pendulum.

8. According to the formula (3.16) to calculate the acceleration of gravity.

9. Ensure that the length of the periods of physical and mathematical pendulums coincide.