CN204375285U - For studying the device that magnetic post is toppled over - Google Patents

Abstract

The utility model belongs to kinetics research device field, especially the dynamics device of research involved by circular motion.Fine rule is fastened a weight and is moved in a circle at perpendicular, experimental phenomena and theoretical situation about not being inconsistent are there is, in order to explain this phenomenon and certification theory correct, the utility model proposes a kind of device: for studying the device that magnetic post is toppled over, comprise vertical panel, base, vertical panel is fabricated from iron, also comprise magnetic post, the upper end of fine rule is bolted to magnetic post, the lower end of fine rule hangs spherical weight, it is characterized in that: vertical panel is fixedly connected with one for making weight not be subject to fine rule pulling force behind equilibrium position and retraining the track of weight motion, described track is provided with arc-shaped rail, arc-shaped rail upper end is fixedly connected with catch, catch is fixedly connected with elastic card.

Description

For studying the device that magnetic post is toppled over

Technical field

The utility model belongs to kinetics research device field, especially the dynamics device of research involved by circular motion.

Background technology

Fine rule is fastened a weight and is moved in a circle at perpendicular, weight pulling force when minimum point is greater than gravity, and minimum point pulling force maximum-this is all easily by theoretical proof, want by this phenomenon of experiment performance, prior art discloses a kind of device studying circular motion: vertical panel, be positioned at vertical panel lower end for supporting the base of vertical panel, vertical panel is made up of iron plate, also comprise one to be made up of permanent magnet, shape is the magnetic post of column, magnetic post one end is adsorbed in vertical panel, magnetic post other end bolt fine rule, the upper end of fine rule is bolted to magnetic post, the lower end of fine rule hangs a weight.The using method of this device: the first step, rises certain altitude by weight, and: 1, make fine rule be in linear state; 2, fine rule departs from vertical position.Second step, release weight, weight starts to do the motion that shape is circular arc, that is: a part for circular motion.Select suitable off-position, such effect can be reached: at this position release weight, just magnetic post can be forgotten about it.Theoretical analysis is as follows: represent with T the pulling force that weight is subject to, and represent with G and represent the quality of weight with m by the gravity that weight is subject to, represent the speed of weight through minimum point with v, represent the radius of weight circular motion with r, derivation obtains so, obtain minimum point speed v larger, the conclusion that pulling force T is larger.Explain with this experiment is auxiliary: magnetic post is forgotten about it, and illustrates that pulling force T force of gravity is large.Experimental implementation person recorded the video of this experiment, when playing video frame by frame, finds: magnetic post is not used in weight and is in minimum point and falls down, but obviously have passed through after minimum point, and magnetic post just.Experimental implementation person repeats experiment repeatedly, and all recorded video is also play frame by frame at every turn, all finds this phenomenon.This phenomenon and theory are not inconsistent.Do not found by people before this phenomenon: slow play just can observe this phenomenon.Outwell to magnetic post through minimum point from weight, approximately last 0.2 second.The time of 0.2 second, be approximately this device hang 1/8th of weight period of single pendulum, in this 0.2 second, the distance of weight process is approximately 2/3rds of amplitude, and the angle of fine rule and vertical direction is approximately 40 degree.So usually do not go out this phenomenon from observation the time, when slow play, the distance that can depart from equilibrium position from weight observes this phenomenon.

Strict, this experiment and theory are not inconsistent, and this experimental provision should not be used for the dynamic (dynamical) teaching of circular motion.In other words: a new device be researched and developed, the experiment that minimum point pulling force is greater than gravity can be demonstrated, and overcome above-mentioned defect.

Since research and develop new device, where is the problem will to know existing apparatus.Have two kinds of sayings: 1, the deformation of fine rule needs the time, and this time is approximately 0.2s, waits fine rule to complete deformation, and magnetic post is just subject to larger pulling force and is forgotten about it.2, magnetic post just starts to have toppled over through minimum point at weight, but the length of magnetic post falls short of, and after 0.2 second, just obviously finds out magnetic post and outwells.These two kinds of sayings sound all reasonable, if judge which kind of saying is correct with knowwhy, this is very complicated theoretical question.

About this phenomenon, also have other to explain, those explanations directly can be got rid of by theoretical analysis, so, just do not describe in this manual.

The utility model proposes a kind of device, this device can: 1, which kind of is correct to verify above-mentioned two kinds of sayings.2, overcome the weak point of existing apparatus, and reach experimental phenomena and the theoretical beneficial effect conformed to.

Utility model content

The utility model overcomes the not enough technical scheme adopted of prior art:

For studying the device that magnetic post is toppled over, comprise vertical panel, be positioned at vertical panel lower end for supporting the base of vertical panel, vertical panel is fabricated from iron, also comprise that be made up of permanent magnet, shape is a column magnetic post, magnetic post one end is adsorbed in vertical panel, magnetic post other end bolt fine rule

The upper end of fine rule is bolted to magnetic post, and the lower end of fine rule hangs the spherical weight that is used for doing circular motion, it is characterized in that:

Vertical panel is fixedly connected with one for making weight not be subject to fine rule pulling force behind equilibrium position and retraining the track of weight motion, and described track is such:

Track be provided with for retrain weight motion arc-shaped rail, arc-shaped rail is circular arc at the section shape of perpendicular, each tangent plane in arc-shaped rail place perpendicular to vertical panel,

The radius-of-curvature of arc-shaped rail is less than the radius of trajectory,

Arc-shaped rail tangent line is bottom horizontal direction, arc-shaped rail lowest positions a little less than the minimum point of trajectory,

The distance of arc-shaped rail upper end distance magnetic post is less than the radius of trajectory,

Arc-shaped rail upper end be fixedly connected with one perpendicular to guide rail, for stopping that weight continues the catch upwards swung,

Catch be fixedly connected with two panels relative, be arranged in parallel, for blocking the elastic card of weight, elastic card does not contact with arc-shaped rail, elastic card place plane is perpendicular, elastic card respectively has relative, for stoping weight to slide a projection at its inlet internal, and the horizontal range of two projections is less than the diameter of weight.

The arc length arriving upper end process along arc-shaped rail is bottom 1 to a thirtieth/10th of fine rule length.

Magnetic post shapes is right cylinder.

Catch also sticks the cushion for cushioning weight.

Cushion is made up of sponge.

Arc-shaped rail is flake.

The utility model structure is simple, does related experiment, experimental phenomena can be allowed to conform to theoretical analysis perfection with the utility model.

Accompanying drawing explanation

Fig. 1 is the front elevation of prior art.

Fig. 2 is the test pattern of prior art.

Fig. 3 is the front elevation of the utility model embodiment one.

Fig. 4 is the partial elevation view of the utility model embodiment one.

Fig. 5 is the partial structurtes schematic diagram of the utility model embodiment one.

Fig. 6 is the partial top view of the utility model embodiment one.

Fig. 7 is the partial top view of the utility model embodiment two.

In figure: 1-vertical panel, 2-base, 3-magnetic post, 4-fine rule, 5-weight, 51-trajectory, 6-track, bottom, 62-arc-shaped rail, 63-arc-shaped rail upper end, 64-elastic card, 641-is protruding, 65-catch, 66-cushion for 61-arc-shaped rail.

Embodiment

Accompanying drawing 1,2 is front elevation and the side view of prior art respectively: prior art comprises vertical panel 1, be positioned at vertical panel 1 lower end for supporting the base 2 of vertical panel 1, vertical panel 1 is fabricated from iron, also comprise that be made up of permanent magnet, shape is a column magnetic post 3, magnetic post 3 one end is adsorbed in vertical panel 1, magnetic post 3 other end bolt fine rule 4, the upper end of fine rule 4 is bolted to magnetic post 3, and the lower end of fine rule 4 hangs the weight 5 that is used for doing circular motion.

Embodiment one

See accompanying drawing 3, it is front elevation of the present utility model, for studying the device that magnetic post is toppled over, comprise vertical panel 1, be positioned at vertical panel 1 lower end for supporting the base 2 of vertical panel 1, vertical panel 1 is fabricated from iron, also comprise that be made up of permanent magnet, shape is a column magnetic post 3, magnetic post 3 one end is adsorbed in vertical panel 1, magnetic post 3 other end bolt fine rule 4

The upper end of fine rule 4 is bolted to magnetic post 3, and the lower end of fine rule 4 hangs the spherical weight 5 that is used for doing circular motion, it is characterized in that:

Vertical panel 1 is fixedly connected with one for making weight 5 not be subject to fine rule 4 pulling force behind equilibrium position and retraining the track 6 of weight 5 motion.Described track 6 is such: (see accompanying drawing 4, be the front elevation of this track 6, accompanying drawing 5 is structural representations of this track 6, and accompanying drawing 6 is vertical views of this track 6.）

Track 6 be provided with for retrain weight 5 move arc-shaped rail 62, arc-shaped rail 62 is circular arc at the section shape of perpendicular, each tangent plane in arc-shaped rail 62 place perpendicular to vertical panel 1,

The radius-of-curvature of arc-shaped rail 62 is less than the radius of trajectory 51,

Arc-shaped rail bottom 61 tangent line be horizontal direction, arc-shaped rail bottom 61 positions a little less than the minimum point of trajectory 51,

Arc-shaped rail upper end 63 is less than the radius of trajectory 51 apart from the distance of magnetic post 3,

Arc-shaped rail upper end 63 be fixedly connected with one perpendicular to guide rail, for stopping the catch 65 that weight 5 continues upwards to swing, catch 65 place plane orthogonal in perpendicular,

Catch 65 be fixedly connected with two panels relative, be arranged in parallel, for blocking the elastic card 64 of weight 5, elastic card 64 does not contact with arc-shaped rail 62, elastic card 64 place plane is perpendicular, elastic card 64 respectively has a diameter relative, be less than weight 5 for the horizontal range of projection 641, two projection 641 stoping weight 5 to slide at its inlet internal.

Explain: trajectory 51, when trajectory 51 refers to that weight 5 does circular movement (also can be called simple harmonic motion, be also one section of arc of circular motion simultaneously), the track of the process bottom of weight 5.Naturally, trajectory 51 is one section of circular arc.

Using method: magnetic post 3 is adsorbed in vertical panel 1, weight 5 is allowed to depart from equilibrium position, and guarantee that the shape of fine rule 4 is straight line, and guarantee that fine rule 4 is parallel to vertical panel 1, then weight 5 is discharged, many experiments, finds this position: when this position release weight 5, weight 5 can forget about it magnetic post 3 just when circular motion.Mark this position.In order to the convenience stated, this position is designated as A position.

Pinch weight 5 with hand, make weight 5 be positioned at A position, then start this experiment shooting.

Release weight 5, fine rule 4 is just after vertical direction, weight 5 just enters arc-shaped rail 62 immediately, weight 5 is once contact with arc-shaped rail 62, and fine rule 4 pulling force just reduces, and weight 5 continues to move along arc-shaped rail 62 due to inertia, fine rule 4 pulling force disappears, lose the pulling force of fine rule 4 to weight 5 through equilibrium position from weight 5, the arc length of process very short, the time experienced is also very short.Time weight 5 arrives arc-shaped rail upper end 63, enter the region that elastic card 64 surrounds, owing to being provided with catch 65, so weight 5 can not go out arc-shaped rail 62, because: elastic card 64 respectively has relative, for stoping weight 5 to slide a projection 641 at its inlet internal, the horizontal range of two projections 641 is less than the diameter of weight 5, so weight 5 also can not slide again.

The above-mentioned video of slow play, can see: fine rule 4, through vertical direction, enters arc-shaped rail 62, and fine rule 4 almost starts to bend simultaneously----that is pulling force disappearance.Magnetic post 3 still keeps horizontal direction to be adsorbed on vertical panel 1, through the time of about 0.2 second, obviously observes magnetic post 3 topple over from video.

Illustrate thus: 1, do this experiment by prior art and do not see that weight 5 forgets about it magnetic post 3 when minimum point, not because the deformation of fine rule 4 needs the reason of corresponding time, but because toppling over of magnetic post 3 is a process from slow to fast, the starting stage of toppling over, even if slow motion plays video, be also difficult to find that magnetic post 3 is obviously toppled over.Use device described in the utility model, can prove: weight 5 when minimum point, pulling force truly have maximal value, and pulling force is greater than the gravity of weight 5.

Embodiment two

Based on embodiment one, the utility model can be optimized like this: catch 65 also sticks the cushion 66 for cushioning weight 5.Cushion 66 can be made up of sponge.Cushion 66 can reduce the speed of weight 5.See Fig. 7.

To further explanation of the present utility model:

In order to allow weight 5 behind equilibrium position, fine rule 4 pulling force that allows as early as possible disappears, and can limit like this: 61 be 1 to a thirtieth/10th of fine rule 4 length to the arc length of upper end process bottom along arc-shaped rail.Such restriction, just can get rid of " because fine rule 4 deformation needs the time just to cause magnetic post 3 to postpone to topple over ".

Can also optimize like this:

Magnetic post 3 shape can be right cylinder.

Arc-shaped rail 62 is flake.

The each tangent plane in arc-shaped rail 62 place is perpendicular to vertical panel 1, because arc-shaped rail 62 is curved surfaces, so not talkative curved vertical is in vertical plane, and says that each tangent plane of curved surface is perpendicular to perpendicular.

The radius-of-curvature of arc-shaped rail 62 is less than the radius of trajectory 51, the words says, weight 5 moving radius is allowed to reduce, fine rule 4 pulling force can be allowed to be 0, so, magnetic post 3 only under tension before fine rule 4 swings to vertical position can be guaranteed, after fine rule 4 swings to vertical position, weight 5 enters track 6 as early as possible, and weight 5 is supported by arc-shaped rail 62, and the pulling force of fine rule 4 disappears.Strictly speaking, fine rule 4 is after vertical position, and in extremely short time, very short arc length, fine rule 4 pairs of magnetic posts 3 still have pulling force, but, still can reach the technical problems to be solved in the utility model.For example: time weight 5 freely swings, after vertical position, continue swing 40 degree of angle magnetic posts 3 to topple over, employ device described in the utility model, fine rule 4 is after vertical position, be less than when 5 degree at continuation pendulum angle, weight 5 just enters track 6, cause that fine rule 4 is bending, pulling force disappears, but magnetic post 3 has still been outwelled, this has just illustrated, outwelling of magnetic post 3, because fine rule 4 deformation needs the reason of time, but magnetic post 3 to outwell be a reason from slow to fast.

Arc-shaped rail bottom 61 tangent line be horizontal direction, arc-shaped rail bottom 61 positions a little less than the minimum point of trajectory 51, " summary " word, normally unclear statement.But after various equivalent modifications has seen this instructions, be appreciated that this slightly word, this slightly means this: the condition that elastic force produces has two necessary factors: 1, contact, 2, there is deformation.In actual mechanical process, only contact does not still have deformation so that do not have elastic force to be difficult to accomplish, so, arc-shaped rail bottom 61 positions a little less than the minimum point of trajectory 51, in other words allow weight 5 behind equilibrium position, as early as possible enter arc-shaped rail 62, then, fine rule 4 is subject to the elastic force that arc-shaped rail 62 applies, then fine rule 4 is allowed not to be subject to elastic force, if allow weight 5 in just past equilibrium position just and arc-shaped rail 62 create elastic force, so, the elastic force of fine rule 4 can change because there being the holding power of arc-shaped rail 62.In other words: time weight 5 is just past equilibrium position, weight 5 does not contact with arc-shaped rail 62, weight 5 just through equilibrium position, just having touched arc-shaped rail 62 and being subject to the elastic force that arc-shaped rail 62 applies as early as possible.Such explanation, various equivalent modifications just can understand the implication of slightly word.If the summary word of also feeling belongs to unclear statement, can limit: arc-shaped rail is 61 positions 0.1mm-2mm lower than the minimum point of trajectory 51 bottom.

Elastic card 64 does not contact with arc-shaped rail 62, this technical characteristic is such meaning: if elastic card 64 contacts with arc-shaped rail 62, just cause: weight 5 is when entering the region that elastic card 64 and catch 65 surround, enter difficulty to increase, once successfully not enter, will slide, so again through equilibrium position, such motion process is very complicated.Meanwhile, the motion process that such motion process neither be studied, so elastic card 64 does not contact with arc-shaped rail 62, the region that weight 5 can be allowed to be relatively easy to enter elastic card 64 and catch 65 surround.It is that two elastic cards 64 are opened in exclusion that weight 5 enters elastic card 64, and elastic card 64 does not contact with arc-shaped rail 62, is convenient to weight 5 exclusion and opens this two elastic cards 64.

Elastic card 64 respectively has a diameter relative, be less than weight 5 for the horizontal range of projection 641, two projection 641 stoping weight 5 to slide at its inlet internal.Weight 5, due to inertia, has poured the region that elastic card 64 and catch 65 surround, but rethink when rolling down, speed reduces, and cannot again break through elastic card 64, also would not slide along arc-shaped rail 62.So, need to arrange protruding 641.

Various equivalent modifications should be known: accurately enter elastic card 64 to allow weight 5, two elastic cards 64 should be lived apart in the both sides of weight 5 movement locus, and identical apart from the length of weight 5, that is: the center line of elastic card 64 belongs to the inswept perpendicular of fine rule 4.

Fine rule 4 length can be 1m.

The utility model structure is simple, is beneficial to and probes into more dynamic (dynamical) problems, as complementary experimental provision, can accomplish that experimental phenomena conforms to theory.

Claims (1)

1. for studying the device that magnetic post is toppled over, comprise vertical panel, be positioned at vertical panel lower end for supporting the base of vertical panel, vertical panel is fabricated from iron, also comprise that be made up of permanent magnet, shape is a column magnetic post, magnetic post one end is adsorbed in vertical panel, magnetic post other end bolt fine rule

The upper end of fine rule is bolted to magnetic post, and the lower end of fine rule hangs the spherical weight that is used for doing circular motion, it is characterized in that:

Vertical panel is fixedly connected with one for making weight not be subject to fine rule pulling force behind equilibrium position and retraining the track of weight motion, and described track is such:

Track be provided with for retrain weight motion arc-shaped rail, arc-shaped rail is circular arc at the section shape of perpendicular, each tangent plane in arc-shaped rail place perpendicular to vertical panel,

The radius-of-curvature of arc-shaped rail is less than the radius of trajectory,

Arc-shaped rail tangent line is bottom horizontal direction, arc-shaped rail lowest positions a little less than the minimum point of trajectory,

The distance of arc-shaped rail upper end distance magnetic post is less than the radius of trajectory,

Arc-shaped rail upper end be fixedly connected with one perpendicular to guide rail, for stopping that weight continues the catch upwards swung,

Catch be fixedly connected with two panels relative, be arranged in parallel, for blocking the elastic card of weight, elastic card does not contact with arc-shaped rail, elastic card place plane is perpendicular, elastic card respectively has relative, for stoping weight to slide a projection at its inlet internal, the horizontal range of two projections is less than the diameter of weight

Arc-shaped rail is flake.