CN200962266Y - Rigid body moment inertia experimental device - Google Patents

Abstract

The utility model belongs to physics experimental device, particularly relates to a experimental device of the moment of inertia of rigid body, which mainly comprises a platform (18), a frame (1), a weight counterbalance rod (4), a cone pulley (23), a weight counterbalance mass (5), a stay wire (10), a guide wheel (11) and a weight hook (15), wherein a photoelectric door frame is placed on the platform (18). The photoelectric door frame is formed by that a photoelectric doorpost (17) is fixed on a photoelectric door seat (19), a spring (20) is installed inside the photoelectric doorpost (17), a photoelectric door rod (9) is installed on the spring (20), and the portion between the photoelectric door rod (9) and the photoelectric doorpost (17) is movably connected together by a photoelectric doorpost cover (16) and by using thread connection, an photoelectric door (8) is fixed on the upper end of the photoelectric door rod (9), sensors (7) are arranged on the standing plates which is on both sides of the photoelectric door (8), the sensors (7) are fixed on the standing plates by nuts. The experimental device reduces the accident error of the process of experiment markedly, and the device is simple, the operation is convenient.

Description

The solid moment of inertia experimental provision

Technical field

The utility model belongs to physics facility, particularly a kind of solid moment of inertia experimental provision.

Technical background

At present, traditional solid moment of inertia experiment, its experimental apparatus is solid moment experimental device, electronic instrument, vernier caliper and meter ruler etc., owing to examine with observing, manually measure, the accidental error that produces is bigger; Simultaneously, also exist owing to ignored the systematic error of the generations such as the moment of resistance of rigid body dead axle rotation.

Summary of the invention

The purpose of this utility model is to overcome above-mentioned technical deficiency, and a kind of photogate and digital millisecond counter Measuring Time, solid moment of inertia experimental provision of control automatically of adopting is provided.

The technical scheme that the utility model technical solution problem adopts is: a kind of mainly by platform, frame, weight linear meter, cone pulley, balancing weight, backguy, the solid moment of inertia experimental provision that guide wheel and weight hanger are formed, be characterized on platform, placing a photoelectricity door frame, the photoelectricity door frame is by fixing a photoelectricity door pillar on the photoelectricity gate seat, adorn a spring in the photoelectricity door pillar, adorn a photogate bar above the spring, cover versatilely with being threaded togather with the photogate post between photogate bar and the photoelectricity door pillar, a photogate is fixed in photogate bar upper end, photogate two risers are equipped with sensor, and sensor is fixed on the riser with nut; Fix a fork-shaped shadow shield at balancing weight one end.

The beneficial effects of the utility model are: this experimental provision, owing to eliminated the systematic error that produces by the friction square; Owing to adopted automatic control,, greatly reduced the accidental error of experimentation with photogate and digital millisecond counter Measuring Time; Equipment is simple, easy to operate.

Description of drawings

Specify with embodiment below in conjunction with accompanying drawing.

Fig. 1 shows solid moment of inertia experimental provision front view.

The vertical view of Fig. 2 diagrammatic sketch 1.

Fig. 3 shows the shadow shield part drawing.

Among the figure, the 1-frame; The 2-setting nut; The 3-axle seat of honour; The 4-weight linear meter; The 5-balancing weight; The 6-shadow shield; The 7-sensor; The 8-photogate; 9-photogate bar; The 10-backguy; The 11-guide wheel; The 12-wheel frame; The 13-set bolt; The 14-weight hanger; The 15-counterweight; 16-photoelectricity door pillar lid; 17-photoelectricity door pillar; The 18-platform; 19-photoelectricity gate seat; The 20-spring; The 21-step pulley shaft; Following of 22-axle; The 23-cone pulley; The 24-feet;

Embodiment

With reference to accompanying drawing, a kind of solid moment of inertia experimental provision, mainly by platform 18, frame 1, weight linear meter 4, cone pulley 23, balancing weight 5, backguy 10, guide wheel 11 and weight hanger 15 are formed, its feature is to place a photoelectricity door frame on platform 18, the photoelectricity door frame is by fixing a photoelectricity door pillar 17 on the photoelectricity gate seat 19, adorn a spring 20 in the photoelectricity door pillar 17, adorn a photogate bar 9 above the spring 20, cover 16 versatilely with being threaded togather with the photogate post between photogate bar 9 and the photoelectricity door pillar 17, a photogate 8 is fixed in photogate bar 9 upper ends, photogate 8 vertical plates on both sides are equipped with sensor 7, and sensor 7 usefulness nuts are fixed on the riser; Fix a fork-shaped shadow shield 6 at balancing weight 5 one ends, the width of shadow shield 6 (seeing accompanying drawing 3) is Δ x, adopts adhesive tape to make.Platform 18 1 ends are placed frame 1, frame 1 bottom is provided with the feet 24 that can heighten, adjust its levelness, fix following 22 on an axle below the frame 1, the axle seat of honour 3 of an adjustment height is adorned on top with setting nut, between two seats step pulley shaft 21 is housed versatilely, be fixed with cone pulley 23 and weight linear meter 4 on the step pulley shaft 21, the balancing weight 5 of adjustable distance is equipped with at weight linear meter 4 two ends, and platform 18 other ends are fixed a wheel frame 12 with set bolt 13, adorns a guide wheel 11 on the wheel frame 12 versatilely, backguy 10 1 ends are fixed on the cone pulley 23 desired radiuses, walk around guide wheel 11, the other end is hung a weight hanger 14, loads onto needed counterweight 15 on the weight hanger 14.

The experimental technique of this equipment: after shadow shield 6 passes through photogate 8 for the first time, press photogate 8 immediately, make the shadow shield 6 can not shading, before waiting to reach the design number of turns, photogate 8 is set back under the effect of spring 20, allow shadow shield 6 for the second time by photogate 8, digital millisecond counter has just write down shadow shield 6 twice time Δ t by photogate 8 like this ₁With Δ t ₂, can obtain corresponding instantaneous velocity υ thus ₁And υ ₂, establishing r is the radius of turn of shadow shield 6 apart from rigid body step pulley shaft 21 centers, a is twice acceleration by photogate 8 of shadow shield 6 rotation N circles, then has:

${\mathrm{\υ}}_1=\frac{\mathrm{\Δx}}{t_1};$ ${\mathrm{\υ}}_2=\frac{\mathrm{\Δx}}{\mathrm{tx}}.$ Again ${\mathrm{\υ}}_2^2-{\mathrm{\υ}}_1^2=2\mathrm{as};$

In the formula: S=2 π γ N

∴ $a=\frac{{\mathrm{\υ}}_2^2-{\mathrm{\υ}}_1^2}{4\mathrm{\πNr}}---1$

If rigid body (cone pulley 23, step pulley shaft 21, weight linear meter 4 and balancing weight 5) quality is m, tension force is T in the backguy 10, and the acceleration of rigid motion is a _m, the rotational resistance torque of rigid body axle is M _f, the rotary inertia of rigid body is I, the angular acceleration of Rigid Body in Rotation With is β, and the radius R of the cone pulley 23 that backguy 10 is fixed, by analysis:

mg-T＝mam......2；

TR-M _f＝Iβ......3；

a _m＝Rβ......4；

2,3,4 formula simultaneous get: mgR=M _f-β (mR ²+ I) ... 5

Two kinds of methods of Measuring Moment of Inertia Using:

One, with β=α/γ substitution 5 formulas, can get $\mathrm{mgR}=M_f+\left(\frac{\mathrm{<figure-callout\; id="2"\; label="m\; R"\; filenames="Y20062009394400071.png,Y20062009394400072.png"\; state="\{\{state\}\}">m</figure-callout>}{R}^{}{}^2+I}{\mathrm{\&gamma;}}\right)a\&CenterDot;\&CenterDot;\&CenterDot;\&CenterDot;\&CenterDot;\&CenterDot;6;$ Change m (or R) and can get different a values.Any two groups of data (m _na _n) and (m _N+1a _N+1) difference substitution 6 formula simultaneous, but cancellation M _fItem is obtained I.

Two, formula is out of shape: $\mathrm{MR}(g-\frac{R}{r}a)=M_f+\frac{I}{r}a\&CenterDot;\&CenterDot;\&CenterDot;\&CenterDot;\&CenterDot;\&CenterDot;7;$ (mgR a) obtains slope I/r value with regard to 7 formulas with least square method, can get the I value in conjunction with r to get the N group.

Claims (1)

1, a kind of solid moment of inertia experimental provision, mainly by platform (18), frame (1), weight linear meter (4), cone pulley (23), balancing weight (5), backguy (10), guide wheel (11) and weight hanger (15) are formed, it is characterized in that going up photoelectricity door frame of placement at platform (18), the photoelectricity door frame is by fixing a photoelectricity door pillar (17) on the photoelectricity gate seat (19), adorn a spring (20) in the photoelectricity door pillar (17), adorn a photogate bar (9) above the spring (20), cover (16) versatilely with being threaded togather with the photogate post between photogate bar (9) and the photoelectricity door pillar (17), a photogate (8) is fixed in photogate bar (9) upper end, photogate (8) vertical plates on both sides is equipped with sensor (7), and sensor (7) is fixed on the riser with nut; Fix a fork-shaped shadow shield (6) at balancing weight (5) one ends.

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