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5
Akhmadjonova U. T. senior teacher Department of Physics Jizzakh Polytechnic Institute Uzbekistan, Jizzakh city
USE OF COMPUTER TECHNOLOGIES IN LABORATORY
EXERCISES
Abstract: In the process of performing laboratory exercises from the mechanics department of physics, the CASSY device connected to a computer is used to determine the amount of centrifugal force. The results obtained in the experiment are directly calculated with the help of computers.
Key words: CASSY device, sensor, computer, centrifugal force, angle, curvilinear motion, linear velocity, angular velocity.
Introduction: It is known that in order to cover the subject of centripetal force, it is first necessary to give students concepts such as linear velocity, angular velocity, centripetal acceleration and tangential acceleration. Students need to pay close attention to building these concepts because they are difficult concepts to master. At the same time, the instantaneous speed known to the students in advance is of particular importance when studying curved motion. In this topic, the main problem of mechanics is solved for the case of the body moving in a circle.
Main part: When an object moves in a circle, a centripetal acceleration is created. Let's apply Newton's laws to the rotational motion of an object.
An object moving uniformly along a circle has an acceleration. Such
■d2
acceleration is called centripetal acceleration. a= — (1) if we put this formula
into Newton's second law F= ma (2) we get F= m— (3) and this formula represents the centripetal force or the formula can be expressed as follows: d =
w • R (4) from the fact that F= m —— = mw2 • R (5)
The centripetal force acting on an object is directly proportional to the mass and the square of the linear velocity of the object, and inversely proportional to the radius of rotation.
When we spin a ball tied to a string, we act on it through the string. We pull the ball to the center with the force of the thread. The larger the mass of the ball, the more force we need to pull it. The square of the ball's linear velocity increases, the more force is required to pull it. But the longer the thread, that is, the larger the radius of rotation, the less force is required to pull the ball [5-6].
Newton's third law can also be applied to rotational motion. According to Newton's third law, centripetal force is equal in magnitude, but there is also a
force opposite to it in direction, and this force is called centrifugal force. Centrifugal force, like centripetal force, is expressed as:
(uR)2 2 D iC\
F= - = • A (6)
Centrifugal force is directed outwards from the center of rotation along a radius.
A force that restricts the free movement of a material point (body) and forces it to move along a curve.
For example, if a stone (material point) attached to a rope is rotated in a horizontal plane, the centripetal force acts on the stone from the side of the rope, forcing it to move in a circle. Centrifugal force acts on the rope from the side of the stone, and it can tighten the rope and even break it.
Centrifugal force can be performed using information technology, that is, with the help of a computer. For this we use CASSY Lab 2 help menu. Laboratory work is performed on the Pocket-CASSY device.
Figure 1. Centrifugal power device.
The centrifugal force device F experimentally studies the dependence of the centrifugal force on the body m mass located at the point r. Centrifugal force acting on a body rotating at an angular velocity ro at a distance r from the center of rotation is determined as follows.
F = mu2 • R (7)
The centrifugal force device is fixed to the table with clamps. The centrifugal force device is placed in such a way that the rotating rod can easily pass between the lever with the U-shaped sensor. But it is necessary that the body of mass m does not block the light passing through the U-shaped gap. The centrifugal force device is connected to input B, the light sensor is connected to input A of the timer housing Sensor-CASSY with a 6-pin cable. The centrifugal force is connected to the power supply by two cables. In a centrifugal force device, the centrifugal force F acting on a load of mass m attached to the rod is transmitted through the rod and to the tensioner mounted on the rotating shaft.
The force applied to the tensioner is measured electrically. At the accuracy level intended for the experiment, the deformation of the spring is elastic, and the coefficient of deformation F is proportional to the force.
The composition of the device
1.CASSY-sensor 524 010 or 524
2.CASSY Lab2 013 524 220
3. Timer adapter or S-Timer 524 034 or 524
4. Centrifugal power device-S 074 524 068
5. Supply source 521 49
6. Horn-shaped light sensor 337 46
7. Multi-core cable, 6-core501 16
8. Clamp with handle301 06
9. Sterjen base-base, U-shaped, 20 cm300 02
10. Sterjen column, 10 cm300 40
11. Pair of cables, 50 cm, red and blue501 45
12. Computer with Windows XP/Vista/7/8 OS installed
Even if the existing centrifugal force device (347 21) is upgraded with a centrifugal force coupling (524 0681), the way of processing measurements and results does not change and does not differ with the S-centrifugal force device. Before using the Centrifugal Power Unit (347 21) with the Centrifugal Power Coupling (5240681), the zero position and force multiplier must be set according to the Centrifugal Power Coupling manual..
When the rotary handle is at rest, the power on the screen is set to 0. To do this, press the Settings Force FBI button on the centrifugal force
device (with the right mouse button).
Install compensating loads on the short arm of the device so that the measured force F is the same as when applied without load but with safety screws.
The supply voltage of the system should be provided in such a way that the measured force value should not exceed 15N. Apply the voltage to 1.5v, start the experiment with a low angular velocity ro and count the number of revolutions. By increasing the voltage to 3v, the measurement is continued at a higher angular velocity.
When carrying out a series of measurements, measurements are carried out in the case of changing the mass m (r=const) and changing r (m=const).
To do this, select Measurement ^ Append New Measurement Series and start with small angular velocities.
The working formula of the laboratory exercise is derived from the
■2
following formula F= m — (8). First, $ in the formula is found
$ = - = — = = (9)by plugging the found value into (8), W
4 n2RN2m
F = ——— (10) is generated.
In the resulting formula, R is the distance from the center to the load, N is the number of rotations, m is the mass of the load, and t is the time taken to rotate N times.
The results obtained on the computer are calculated using the formula (10), and it is determined that the values of the centrifugal force F and w2 are in a linear relationship. The obtained results are used in all rotating devices, especially in wind electric motors.
Conclusion: Centrifugal force is split with Pocket-CASSY on a computer with the ability to obtain the final result quickly and with high accuracy. This program can be used by students of higher educational institutions, colleges and academic lyceums for automatic processing of physics laboratory works.
References:
1. Мустафакулов, А. А., Халилов, О. К., & Уринов, Ш. С. (2019). Цель и задачи самостоятельной работы студентов.
2.Жураева, Н. М., & Ахмаджонова, У. Т. (2021). Использование творческой работы в кругах. Экономика и социум, (3-1), 552-555.
3. Axmadjonova, Y. T., & Axmadjonova, U. T. (2021). O'quv dars mashg'ulotlarida didaktik o'yin texnologiyalaridan foydalanish. Science and Education, 2(11), 977-984.
