自由落体

A graph of average speeds versus time can give the acceleration due to gravity of the falling object.

平均速度——时间图表可以给出这个自由落体的重力加速度。

The instrument for measuring acceleration of gravity is redesigned.

1引言目前，测量重力加速度的方法有单摆法和自由落体法。

Galileo is said to have conducted his revolutionary experiments with falling objects from the off-kilter belfry.

伽利略曾在这个失去平衡的倾斜的钟楼上做过具有划时代意义的自由落体实验。

Pascal French scientists found that the pressure of liquids and gases in the dissemination of law; British scientists found that gas pressure Boyle's law.

物理学 伽利略通过多次实验发现了自由落体、抛物体和振摆三大定律，使人对宇宙有了新的认识。

The experimental TBI model was established by bumpiness of free falling bady according to Feeneys.

按Feeney自由落体撞击法建立大鼠创伤性脑损伤模型。

Methods The experimental TBI model was established by bumpiness of free falling body according to Feeney′s.The rats′cerebral edema were imaged with magnetic resonance image,The changes of brain water content and permeability of blood-brain barrier were measured by the methods of wet and dry weight and Evans blue fluorometry.The expression of AQP-4 mRNA was examined by reverse transcriptase polymerase chain reaction.

按照改进的Feeney自由落体撞击法建立大鼠创伤性脑损伤模型，用磁共振成像对大鼠脑水肿进行检测，干/湿比重法和伊文思蓝测定法观察大鼠TBI后不同时相脑组织含水量和BBB通透性的变化，并采用逆转录聚合酶链反应法检测AQP-4 mRNA的表达，蛋白质免疫印迹法检测AQP-4蛋白的表达。

Variations in G are not only present in Cavendish experiments and free fall setups.

G 值的变化并不仅仅存在于 Cavendish 的实验和自由落体装置中。

A strip block is used instead of the ball to eliminate the measurement error caused by the trajectory deviation of the ball when passing the photo gate.And a spring clip is used to replace the electromagnet to eliminate the effect of remanence.

在单摆法中，要求忽视细线的质量且线长及小球尺度相比很大，把小球看成质点，并且小球的摆幅不能超过5°[1~3]；在自由落体法中，一般是用小球作为自由落体，但小球通过光电门时，往往不是小球的质心遮光计时，另外，钢球是用电磁铁通电后吸住的，由于断电的瞬间，电磁铁有剩磁，钢球不立即下落，并且钢球应吸在电磁铁的中心处，这些因素都会影响重力加速度的测量。

Editor this segment Culture, Galileo's free fallers experiment Legend, was born in 1590 Pisa's Italian physicist Galileo, once in Pisa in free fall, two experiments of different weights from the same height and ball down, the ball at the same time, two of free fall, and found that the overthrow Aristotle first heavy objects will reach the ground with its head, the speed is proportional to the mass of the view.

编辑本段文化伽利略的自由落体实验传说1590年，出生在比萨城的意大利物理学家伽利略，曾在比萨斜塔上做自由落体实验，将两个重量不同的球体从相同的高度同时扔下，结果两个铅球同时落地，由此发现了自由落体定律，推翻了此前亚里士多德认为的重的物体会先到达地面，落体的速度同它的质量成正比的观点。

The methods testing the WEP usually are torsion pendulum and free falling, the latter one is limited by the height of experiment, so the sensitivity of this method can't be improved, thus nowadays the torsion pendulum is mostly used in high sensitivity experiment.

检验弱等效原理的方法多为扭秤方案和自由落体方案，自由落体法由于受到实验高度的限制，使得在地球上的实验精度无法得到进一步提高，因此现在高精度的地面实验大都采用扭秤方案。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。