It takes s for a transmitter on the earth to transmit electromagnetic waves to the moon The known distance between the earth and the moon is 3.84 × 10 ^ 5km ..

The velocity of electromagnetic wave is 3 * 10 to the eighth Power M / s
So t = 3.84 × 10 ^ 5km / 3 * 10 to the eighth Power M / s, and then divide by 2
=0.64s

The electromagnetic wave is transmitted from the earth to the moon, and its reflected wave is received after 2.56s. The distance between the moon and the earth is______ km．

Electromagnetic wave transmission time t = 12 × 2.56s = 1.28s, distance S = VT = 3 × 105km / s × 1.28s = 3.84 × 105km, so the answer is: 3.84 × 105

The distance between the earth and the moon is 3.84 * 10 ^ 5km. How long does it take for astronauts to send electromagnetic waves from the moon to reach the earth?

The speed of light is about 300000 kilometers per second. You can divide it by yourself

The speed of light is about 3x10 cubic meters per second, and the distance between the earth and the sun is about 1.5x10 cubic meters. How much does it take for the sun to shine from the sun to the earth

5 S = 1.11,
V = about 3x10 cubic meters per second,
T = s / v = 1.5x10 of 11 cubic meters / about 3x10 of 8 cubic meters per second
=500 seconds

It is known that the time for sunlight to shine on the earth is 8 minutes and 20 seconds, and the constant of gravity is 6.67 × 10 ^ - 11. Try to estimate the mass of the sun

First of all, it's a challenge
Light propagation time and speed (we all know it) can be calculated the radius of the earth around the sun, r = 15000000000 meters
Gravitation provides centripetal force. GMM / R ^ 2 = MV ^ 2 / R G is known to be 6.67 × 10 ^ - 11, and m on both sides is approximately lost. R has been obtained above
As for V (the speed of the earth around the sun) = distance (2 * 3.14 * r) divided by 365 days, it is 29885.77 meters per second
In this way, only the solar mass m is unknown, and the calculated solar mass is 2.0 × 10 ^ 30 kg
This superscript and subscript can't be typed. Let's make do with it

It is known that the time of sunlight irradiating the earth is 8 minutes and 20 seconds, and the constant of gravity is 6.67x10 ＾ - 11nm ＾ 2 / kg ＾ 2

First calculate the distance from the sun to the earth
L = C (speed of light) * t
Using GM / L ^ 2 = 4 ^ 2 * L / T (revolution time) ^ 2
The answer can then be found

The mass of the earth is m, the radius is r, and the constant of gravity is g. a man-made satellite that moves in a circle around the earth's surface is launched. The speed of the satellite is called the first cosmic speed. This paper tries to deduce the calculation formula of the first cosmic speed expressed by the above quantities, and it is required to write out the derivation basis and process

Because the satellite makes a circular motion around the earth's surface, it can be considered that its orbit radius is the radius r of the earth. The centripetal force provided by gravity for the satellite to make a circular motion is: gmmr2 = mv2r, the first cosmic velocity is: v = GMR. A: the calculation formula of the first cosmic velocity is v = GMR

It is known that the mass of the earth is m, the constant of gravitation is g, and the radius of the earth is Q?

The object's gravity = universal gravitation = the centripetal force when the spacecraft makes a circular motion along the earth's surface, that is, Mg = GMM / R ^ 2 = MV ^ 2 / R, Mg = MV ^ 2 / R, so V ^ 2 = GR, r = 6.37 * 10 ^ 6m, G = 9.8 m / S ^ 2, v = 7.9 km / s. The calculation formula is: V1 = √ gr (M / s), where g = 9.8 (M / s)

It takes s for a transmitter on the earth to transmit electromagnetic waves to the moon The known distance between the earth and the moon is 3.84 × 10 ^ 5km ..