Introduction
In the early stage of physical development, people's measurement of weak effects is difficult, because these weak roles often don't feel. Later, physics Michelle thought of the suspension, to put a briquette needed greater force, and to reverse a suspension, there is a small force to do it. According to this idea, French physicist Coulomb and the UK's science geek Cavin Die have invented the scales independently in 1785 and 1789. Torsom experiments can measure weak effects. The key is that it will enlarge the weak action. On the one hand, a small force can produce a large moment to generate a large force to create a certain angle; On the other hand, a plane mirror is fixed on the suspension. It can reflect the incident light to the scale of the plane of the plane, and the slight twisting of the spans can be reversed from the light of the spot on the scales of the scale. come out.
Verification of the gravitation
British science geek Cavendi believes in the labeling scales invented in 1789, verify the correctness of Newton's universal gravitational law, and measured gravity constant The experimental results of Callidi were very close to modern measurement. It made a truly practical value of the abortion law, and Cavin Dixu was also called the first "people who could be called Earth".
Newton's another great contribution is his law of gravitational law, but how big is it?
At the end of the 18th century, the British scientist Henry Covendi decided to find this gravitation. He put the small metal ball in both sides of a wooden stick (1 feet equal to 0.3048 meters) and hang it with a metal line, this wooden stick is like a dumbbell. The two 350 pounds (1 pound equal to 0.4536 kilograms) of copper balls are placed in quite close to generate sufficient gravity to rotate the dumbbells and torsion metal wires. Tiny rotation is then measured with homemade instruments. The measurement results were amazing and accurate. He measured the parameters of the gravitational constant, and the gravitation constant was about g = 6.67259x10 ^ -11 (N · m ^ 2 / kg ^ 2) usually take G = 6.67 × 10 ^ -11 (N · M ^ 2 / kg ^ 2), on this basis, on this basis, Cavallish calculates the density and quality of the Earth. The calculation of Cavallish is that the mass of the Earth is 6.0 x10 ^ 24kg.
Verify Coulomb 's Law
French physicist Coulomb uses the torque barrier experiment of the invented scale in 1785, and determines the force between charges. Coulomb found that static power and distance square were in the experiment, and he also recognized that the product of static power and electricity is proportional to the complete Coulomb law. Coulomb's law opened the door of the mathematical theory of electricity, so that electrostatic studies entered the new stage of quantitative research, and laid the foundation for the development of electrical theory of Poisson. Coulomb also used a twisted scale to prove the role of the ground magnetic field on the magnetic needle, the torque size and the sinusoidal proportion of magnetic aircraft skewed angle, which constitutes the foundation of the magnetic moment.
Coulomb Law is a law-related law, its index is exactly 2, is related to the Gaussian theorem is correct, so its correctness has experienced experimental test .
Cullen has done a lot of experimental work with a twisted scale device, but it is worth noting that in terms of precision, it is not as good as the law of gravitational law. Both the charged ball in the trial is a limited large tape electrodes, the distance between the two-stranded electric bodies is impossible, so the two-stranded might is considered to be a point charge is not accurate enough, and the charge distribution on the two balls is interposed. Impact, especially the distance between the two-stranded electric balls cannot be accurately measured, and there is still a leakage phenomenon. Therefore, the index of R is 2 + δ in the denominator, and the experimental error of Kurun himself is δ ≤ 0.04, that is, Kurulum law is represented as f = [k * q (1) * q (2)] / R ^ (2 ± 0.04) . British scientist Covendi made δ Δ ≤ 0.02 in 1773.
The latter has improved the experimental device to verify the law of coulomb.
Due to the similarity between the law of gravitation, the similarity between Coulomb's law, the torque barrier experiment is not a method of use.