VA:VB= (B)
(C)aA:aB= 1:4 (D)TA:TB=
3. The speed of the satellite's movement around the earth, v=, where g is the ground gravity acceleration, r is the radius of the earth, and r is the distance from the satellite to the center of the earth. Which of the following statements is true?
(a) As can be seen from the formula, the hovering speed is inversely proportional to the square root of the trajectory radius;
(b) As can be seen from the formula, the farther the satellite is, the easier it is;
(c) The above expression of hovering speed is wrong;
(d) All the above statements are wrong. ( )
4. Geosynchronous satellites refer to artificial earth satellites that are stationary relative to the ground:
(a) It can be directly above any point on the ground, and the distance from the center of the earth can be selected at different values as required;
(b) It can be directly above any point on the ground, but the distance from the center of the earth is certain;
(c) It can only be directly above the equator, but the distance from the center of the earth can be different according to needs;
(d) It can only be directly above the equator and at a certain distance from the center of the earth. ( )
5. It is known which set of data below can calculate the mass m of the earth (the gravitational constant g is known) ().
(a) The period T 1 of the moon's orbit around the earth and the distance R 1 from the moon to the center of the earth.
(b) The height h of the Earth's "synchronous satellite" from the ground.
(c) The period T2 of the earth's orbit around the sun and the distance R2 from the earth to the center of the sun.
(d) The operating speed v and operating period T3 of the near-earth satellite.
6. If the orbit radius of an artificial earth satellite that makes circular motion is doubled and still makes circular motion, then ().
(a) According to the formula V = Ω r, the linear velocity of satellite motion will be increased to twice the original.
(b) According to the formula F=, it can be known that the centripetal force on the satellite will be reduced to the original 1/2.
(c) According to the formula F=, we can see that the centripetal force provided by the earth will be reduced to the original 1/2.
(d) According to the formulas given in b and c above, it can be known that the linear velocity of satellite motion will be restored to its original velocity.
7, artificial earth satellite do uniform circular motion around the earth, let radius of the earth r, ground gravity acceleration for g, the artificial earth satellite ().
(a) The maximum linear speed of the detour route is
(b) The minimum period of the detour is 2π.
(c) When the height from the ground is r, the detour speed is
(d) The period at height r from the ground is 2π.
8. As shown in the picture, there are two planets, A and B, which move in the same direction around the same star O. The period of planet A is T 1, and the period of planet B is T2. When two planets meet for the first time at a certain moment (that is, the two planets are the closest), then ().
(a) After time t=T 1+T2, the two planets will meet for the second time.
(b) As time goes by, the two planets will meet for the second time.
(c) The two planets were far apart for the first time.
(d) The two planets are the farthest apart for the first time.
9. Let the mass of the earth be m, the radius be r, and the angular velocity of its rotation be ω.