A kind of acceleration of gravity measuring instrument
Affiliated technical field
The utility model relates to a kind of acceleration of gravity measuring instrument, is to be used for the experimental apparatus that acceleration of gravity is measured in Physical Experiment.
Background technology
At present, the experimental apparatus of measuring acceleration of gravity has single pendulum method and freely falling body method, in the single pendulum method, require to ignore the quality of fine rule and bead is regarded as a particle, and the amplitude of oscillation of bead can not be above 5 °, so measuring error is bigger, in the freely falling body method, generally be with bead as freely falling body, but bead is when the photogate, often not the barycenter shading timing of bead, so have bigger error yet.
Summary of the invention
Use bead as freely falling body in the acceleration of gravity experimental apparatus in order to overcome existing the measurement, the deficiency that measuring error is big, the utility model provides a kind of acceleration of gravity measuring instrument, this acceleration of gravity measuring instrument uses the bar shaped weight block as freely falling body, the bar shaped weight block is installed on the extension bolt of folder thing device, by the elastic force of spring, the pulling force effect of rope and the free-falling that release knob is controlled the bar shaped weight block.This measuring instrument is rational in infrastructure, globality and good reproducibility, and easy to operate, measuring error is little.
The technical scheme that its technical matters that solves the utility model adopts is: bracing frame (2) lower end is fixed on the base (1), folder thing device (3) is equipped with in the upper end, bar shaped weight block (4) hangs on the folder thing device (3), photogate support (5) is equipped with in the centre of bracing frame (2), photogate (6) is installed on the photogate support (5), photogate (6) is connected with digital millisecond counter (11) by cable, accepting articles (7) is housed on the base (1), bar shaped weight block release knob (8), horizontal adjustment screw (9) and level meter (10), the left end of spring (14) is fixed on the spring anchorage bracket (13), the right-hand member of spring (14) is connected with the left end that the bar shaped weight block is hung bolt (15), the upper end of rope (16) is fixed on the bar shaped weight block and hangs on the left end of bolt (15), after rope (16) is walked around fixed pulley (12), its lower end is fixed on the bar shaped weight block release knob (8), the bar shaped weight block hang bolt (15) at the elastic force of spring (14) and rope (16) but move left and right under the effect of pulling force, bar shaped weight block (4) upper end has hanging hole (17) and the middle window (18) that can hide, the distance L of hanging hole (17) bottom margin bar shaped weight block (4) lower end of having
1=30cM, the distance L of window (18) bottom margin bar shaped weight block (4) lower end
2=15cM.
The beneficial effects of the utility model are: can measure acceleration of gravity easily, and rational in infrastructure, good integrity, easy to operate, good reproducibility, measuring error is little.
Description of drawings
Below in conjunction with drawings and Examples the utility model is further specified.
Fig. 1 is the structural representation of utility model.
Fig. 2 is the structural representation of folder thing device.
Fig. 3 is the structural representation of bar shaped weight block.
1. bases among the figure, 2. bracing frame, 3. folder thing device, 4. bar shaped weight block, 5. photogate support, 6. photogate, 7. accepting articles, 8. bar shaped weight block release knob, 9. horizontal adjustment screw, 10. horizontal steam bubble, 11. digital millisecond counters, 12. fixed pulleys, 13. spring anchorage bracket, 14. springs, 15. bar shaped weight block are hung bolt, 16. rope, 17. bar shaped weight block hanging holes, 18. windows.
Embodiment
In Fig. 1, bracing frame (2) lower end is fixed on the base (1), folder thing device (3) is equipped with in the upper end, bar shaped weight block (4) hangs on the folder thing device (3), photogate support (5) is equipped with in the centre of bracing frame (2), photogate (6) is installed on the photogate support (5), and photogate (6) is connected with digital millisecond counter (11) by cable, and accepting articles (7), bar shaped weight block release knob (8), horizontal adjustment screw (9) and level meter (10) are housed on the base (1).
In Fig. 2, the left end of spring (14) is fixed on the spring anchorage bracket (13), the right-hand member of spring (14) is connected with the left end that the bar shaped weight block is hung bolt (15), the upper end of rope (16) is fixed on the bar shaped weight block and hangs on the left end of bolt (15), after rope (16) is walked around fixed pulley (12), its lower end is fixed on the bar shaped weight block release knob (8), the bar shaped weight block hang bolt (15) at the elastic force of spring (14) and rope (16) but move left and right under the effect of pulling force.
In Fig. 3, bar shaped weight block (4) upper end has hanging hole (17) and the middle window (18) that can hide, the distance L of hanging hole (17) bottom margin bar shaped weight block (4) lower end of having
1=30cM, the distance L of window (18) bottom margin bar shaped weight block (4) lower end
2=15cM.
Close the middle window (18) of bar shaped weight block (4), open bar shaped weight block release knob (8), bar shaped weight block (4) is installed on the extension bolt (15), regulates the position of photogate support (5), make center about 1 centimeters under bar shaped weight block (4) of photogate (6); Regulate the horizontal adjustment screw (9) on the base (1), when the horizontal steam bubble of (10) on the level meter was in the centre position of level meter (10), bracing frame (2) just was in vertical state; Connect digital millisecond counter (11), the plug of the photogate of having pegged graft (6) is pressed the function key of digital millisecond counter (11), selects S
1, make digital millisecond counter (11) be in the record shading state that clocks; Open bar shaped weight block release knob (8), bar shaped weight block (4) free-falling is pressed " stopping " key of digital millisecond counter (11) in accepting articles (7), thumbs the shading time for the first time, is bar shaped weight block (4) free-falling by photogate (6) L
1The time t of distance
1From accepting articles (7), take out bar shaped weight block (4), and open middle window (18), bar shaped weight block (4) is reinstalled in hangs on the bolt (15), repeat said process, measure bar shaped weight block (4) free-falling by photogate (6) L
2The time t of distance
2By
Formula obtain gravity acceleration g.