A question about physical uniform circular motion The trajectory of an aircraft from diving to pulling up is an arc. If the speed of the aircraft on this arc is 150m / s, what is the radius of the arc at least to make its centripetal acceleration at the lowest point less than 5g? G is taken as 10m / s Square

A question about physical uniform circular motion The trajectory of an aircraft from diving to pulling up is an arc. If the speed of the aircraft on this arc is 150m / s, what is the radius of the arc at least to make its centripetal acceleration at the lowest point less than 5g? G is taken as 10m / s Square

a=v²/r
r=v²/a≥150²/50=450(m)
Arc radius at least 450 m

A physics problem about uniform circular motion
One section of the thin line is tied to a heavy object, and the other end of the line is held by hand to make the heavy object move in a uniform circular motion on a smooth horizontal plane. When the speed is the same, is the length of the line easy to break, or is the length of the line easy to break? Why?
If the thin line of the weight is blocked by a nail on the horizontal plane, and then the weight moves around the nail in a circle at a constant speed under the traction of the thin line, when the thin line touches the nail, is it easy to break when the nail is farther away from the weight, or is it easy to break when the nail is closer to the weight? Why?

The first f = V * V / R
V -- speed, R -- line length. The longer R is, the less f is, and it is not easy to break,
The second is the same. The farther away you are, the harder it is to break

When the roller coaster passes through the highest point and there is no pressure on the seat, the speed is v. then when the roller coaster passes through the highest point at the speed of 2V, how many times of the person's weight is the pressure on the seat?
A.1 B.2 C.3 D.5

v2/r = g so (2v)2/r = 4g 4g-g = 3g
The answer is C. This kind of roller coaster is probably the reverse one

It is known that the distance between the moon and the earth is 380000km. Assuming that the period of the moon around the earth is approximately 30d, the rotation period of the moon around the earth is () s, the linear velocity of the moon around the earth is () m / s, and the angular velocity of the moon around the earth is ()
What do you mean by D in the question

D means day

Uniform circular motion
Does uniform circular motion have centrifugal force? Then why do astronauts on satellites in space lose weight

As long as the acceleration goes down, it means weightlessness. And that's gravity acting as a centripetal force, not a centrifugal force. People and satellites have the same acceleration, and there is no interaction between them. That's what we see weightlessness

On physical uniform circular motion
The unit of rotational speed is rad / s or rad / min. if you encounter problems related to rotational speed when doing the question, do you need to convert it into a unified unit and then bring it into the formula? Which unit is it converted into? Thank you^_ ^!

Required, converted to rad / S

On the problem of uniform circular motion
The inner radius R1 of a CD track area is 25 mm, the outer radius R2 is 58 mm, and the radial track density n is 625 pieces / mm. In a CD player, the laser head moves one track along the radial direction every revolution of the CD, and the laser head moves towards the CD at a constant linear speed. If the angular speed of the CD is 50 rad / s at the beginning of playback, what is the angular speed when all the CDs are played? What is the total playback time of the CD?

The radius of the first circle is 25 mm, the radius of the outermost circle is 58 mm, the initial angular velocity is 50 rad / s, and the final angular velocity is X-ray velocity = 25 mm * 50 rad / S = 58 mm * xrad / s 25 * 50 = 58 * x, so x = 25 * 50 / 58 = 21.55 rad / s. when the disc is finished, the angular velocity is 21.55 rad / s 58-25 = 33 mm33 * 625 = 20625

A flat bottom glass weighs 1.2N, has a bottom area of 20 square centimeters, contains 60 cubic centimeters of water, and has a water depth of 5 cm. It is placed on a horizontal plane, g = 10N / kg
Ask: (1) what is the pressure of water on the bottom of the cup?
(2) How much pressure does the cup have on the table

(1) The pressure at the bottom of the cup is equal to the gravity of water, f = 60 * 1 / 1000 * 10 = 0.6N,
According to the calculation formula of liquid pressure, P = 1000 * 10 * 0.05 = 500pa
(2) The pressure on the bottom of the cup is equal to the total gravity of the cup and water, f = 1.2 + 0.6 = 1.8n
According to the pressure calculation, the formula P = f / S = 1.8 / 0.002 = 900pa is defined

Solving physics problems of Grade 8 (about pressure)
When a and B objects are placed on a horizontal table, g a = 4G B, s a = 1 / 2S B, then what is the pressure ratio p a: P B? (the answer is 8:1)

According to the formula: P = f / S
Because it's in the horizontal plane, so f = G
Take the data in, p a = G A / s a = 4G B / 0.5s B = 8 (G B / S B)
P B = G B / S B, so p a = 8p B, that is p a: P B = 8:0

Give you enough water, a measuring cylinder, how to measure the density of small porcelain wine cup (the diameter of the wine cup is smaller than the diameter of the measuring cylinder), please write down the main experimental steps and density expression