Frictional force experiment instrument

Abstract

The invention provides a frictional force experiment instrument, comprising a bottom plate, an object placed on the bottom plate and a spring scale connected with the object through a rope, wherein the spring scale comprises a helical spring and a hollow shell. The frictional force experiment instrument is characterized in that the middle part of the object is provided with a straight hole for the penetration of a horizontal rod and the size of the straight hole should be controlled in a condition that the inner wall of the straight hole cannot make contact with the horizontal rod in the motion process of the object; both the two radial sides of the shell are provided with holes; the shell and the spring penetrate the holes and the horizontal rod penetrating the inner cavity of the spring to be suspended; and the shell is connected with a suspended weight barrel through a rope wound on a pulley. After the structure is adopted, fine weights such as fine sand and the like are considerably added in the weight barrel to pull the object to move at a constant speed, and the experiment can be carried out through changing the rough bottom plate below the object and increasing / decreasing the pressing blocks on the object. The experiment principle of the invention is same as the scheme in the textbook, and the invention has the advantages of simple principle, easy understanding of the students, convenient operation, approximately constant speed of the object and excellent effect.

Description

Technical field [0001] The invention relates to a teaching instrument, in particular to a friction force experiment instrument for studying which factors are related to the magnitude of friction force and how the relationship is. Background technique [0002] The friction experiment is a key experiment in junior high school physics. The experimental plans of each version of the textbook are roughly as follows: [0003] 1. Put the object on a horizontal wooden board, hold the spring scale with your hand and pull the animal block horizontally through the rope to make a uniform linear motion, record the reading of the spring scale, measure the gravity of the object, and fill in the data in the designed form. Constantly add weights with known gravity on the cuboid, and repeat the above experiment. When the surface roughness is the same, the relationship between the magnitude of friction and the magnitude of pressure can be studied. [0004] 2. Put the object on a horizontal wo...

AI Technical Summary

Problems solved by technology

[0006] This inspired the teachers to improve, and the more successful and popularized experimental plan is: change the original textbook plan of "the plank does not move, and the spring weighs the animal block" to "the spring weighs not, and the bottom plank is pulled by hand for relative movement". The advantage is that the approximation of uniform speed and the convenience of operation are slightly improved, but it brings greater obstacles in thinking. Teachers need to try to make students understand the relativity of motion, which artificially creates teaching difficulties. Many teachers After weighing the pros and cons, still choose the original textbook plan

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