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How was the mass of the Earth determined for the first time?
The first person credited with “weighing” the Earth was Henry Cavendish (1731-1810.) In 1798 Cavendish measured the force between attracting lead spheres with a torsion balance. He knew the masses of the spheres and how far apart they were. He carefully measured the force between them, which allowed him to calculate G.
How did scientist find the mass of the Earth?
How is Earth mass calculated? Since scientists already know the radius of planet Earth, they used the Law of Universal Gravitation to determine Earth’s mass with respect to the gravitational force on an object on the Earth’s surface. Simply put, this method uses Earth’s radius as the distance.
How does the Cavendish experiment work?
The Cavendish Experiment is a clever way to measure the Gravitational Constant that is stated in the Universal Gravitation Equation. This experiment used a torsion balance device to attract lead balls together, measuring the torque on a wire and equating it to the gravitational force between the balls.
How do we know how much the Earth weighs?
Earth weighs about 13,170,000,000,000,000,000,000,000 pounds (or 5,974,000,000,000,000,000,000,000 kilograms). Since Earth is too big to be placed on a scale, scientists use mathematics and the laws of gravity to figure out Earth’s weight.
How do you calculate the mass of a planet?
The masses of the planets are calculated most accurately from Newton’s law of gravity, a = (G*M)/(r2), which can be used to calculate how much gravitational acceleration (a) a planet of mass M will produce on objects at distance r away.
How did scientists calculate the speed of light?
The speed of light could then be found by dividing the diameter of the Earth’s orbit by the time difference. The Dutch scientist Christiaan Huygens, who first did the arithmetic, found a value for the speed of light equivalent to 131,000 miles per second. The correct value is 186,000 miles per second.
How did Cavendish calculate the volume of the earth?
Cavendish used a carefully constructed experiment that utilized a torsion balance to measure the very small gravitational attraction between two masses suspended by a thin fiber support. Cavendish’s use of the torsion balance to measure the gravitational constant of the Earth, however, was a triumph of empirical skill.
How did they calculate the gravitational constant?
Cavendish experiment …of the value of the gravitational constant, G. In Newton’s law of universal gravitation, the attractive force between two objects (F) is equal to G times the product of their masses (m1m2) divided by the square of the distance between them (r2); that is, F = Gm1m2/r2.
How do scientist measure planets?
The most common is to measure the apparent angular diameter of the planet – how big it looks against the sky – very precisely using a telescope. Combining this with a measure of its distance (deduced from its orbit around the Sun) reveals the planet’s actual size.
Who was the first scientist to measure speed and distance?
Explanation: The speed of light is 299,792,458 meters per second. In physics this number is represented by the letter “c.” The first scientist to measure speed as distance over time was Galileo.