Practical part. 1. Measure length of peg - l

1. Measure length of peg - l.

2. Set a supporting prism 2 on the first value from a table.

3. Set a peg on a bracket 3.

4. Show a pendulum out of position of equilibrium on a corner and to release; to measure time 10 full oscillations. Write down the period of T to the table 8.1.

5. Repeat measurings with other the values a which are indicated in a table 8.1.

Table 8.1

n	/l	, cm	T, s	l, cm
experiment	theory
	0,01
	0,02
	0,03
	0,04
	0,05
	0,1
	0,2
	0,3
	0,4
	0,45

6. After a formula (8.4) to expect the theoretical values of period of T. To compare the experimental and theoretical values of period.

7. On one field (it is desirable on a plotting paper) to build theoretical and experimental graph according to sample, which is presented on fig. 8.2.

8. Find the first derivative of function (8.4) on a parameter. From a condition to find the theoretical value of co-ordinate of a minimum of function; to compare a theoretical value to experimental, found for graphic .

Draw conclusion.

Figure 8.2

Additionally. To build theoretical and experimental graph by a computer.

For more detailed research of a minimum of function (8.4) do the additional measurings of period of oscillations in an interval with a less step (for example - ). Expect the theoretical values of period at those values. Compare a theory to the experiment, building graphic arts. Draw conclusion, in relation to justice of formulas (8.1) – (8.4).

Control questions

1. What harmonic oscillations? Write down differential equalization of harmonic oscillations and his decision.

2. What is physical pendulum? Write down the formula of the period of oscillation of the physical pendulum.

3. Formulate the theorem of Steiner.

4. Draw the graph of the dependence of period of oscillations of peg from distance between the axis of rotation and pegycenter.