Лабораторные работы / Решенная лабораторная по физике 08

The laboratory work № 8.

Determination the force of friction slide.

Had done by the student gr.__220473я__ F.N.S. Pavlov F.E.

Checked by ______________________ date ____________

Purpose: to define the force of friction slide, using laws of conservation of momentum and changing of mechanical energy.

The order of performing a work:

1. To remove shutter pistol in the extreme position. To place a pool in the stem of spring pistol.

2. To move the cylinder aside the stem of pistol before the stop.

3. To make a shot. A moving of a cylinder with the pool to define on the scale of straightedge.

4. To repeat experience 5 times find an average value.

5. To calculate , using formula . Results of measurements to write in tables 1 and 2.

Table N^o1.

	1	2	3	4	5
S, m	0,078	0,075	0,072	0,057	0,064
<S>, m	0,0692

Table N^o2.

X, m	m , kg	m , kg	k, N/m	<S>, m	<>, N	, N	E %
0,024	0,014	0,0524	1000	0,078	0,7785	0,0990
0,024	0,014	0,0524	1000	0,075	0,8096	0,0679
0,024	0,014	0,0524	1000	0,072	0,8434	0,0341	9,202
0,024	0,014	0,0524	1000	0,057	1,0653	0,1878
0,024	0,014	0,0524	1000	0,064	0,9488	0,0713
0,024	0,014	0,0524	1000	0,0692	0,8775	0

The law of conservation of momentum:

Let's consider the system " pool - cylinder ":

(1)

After the shot on the system " pool - cylinder " works the force of friction slide. As a potential energy does not change, to apply the low of changing of mechanical energy:

=>

(2)

Similarly we have for system " spring - shutter - pool ":

(3)

From (1), (2) and (3) =>

(4)

Conclusion:

So we have studied to define the force of friction slide, using laws of conservation of momentum and changing of mechanical energy.

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