A person travelling in a fast spaceship measures the distance between the earth and the moon. Is it the same, smaller or larger than the value quoted in this book?

Explain parallax method to measure distance between the earth and planet.

In modern times which method is used to measure the distance between the earth and planet?

How many times the value of gravitational acceleration on Moon is lesser than the value on Earth ?

Spacemen Fred's spaceship (which has negligible mass) is in an elliptical orbit about planet Bob. The minimum distance between the spaceship and the planet is R, the maximum distance between the spaceship and the planet is 2R. At the point of maximum distance, spaceman fred is traveling at speed v_(0) . he then fires his thrusters so that he enters a circular orbit of radius 2R. what is his new speed?

In the figure there is a long horizontal bridge over a river 75 m high from water surface. A strong man throws a stone in the parallel plane of the bridge. A observer in a car travelling on the bridge finds the stone going pass by the car while ascending and also while descending between two points on the road 30 m away. The car is travelling at a speed of 15 m/s. The stone is thrown from the bank of river just at the same level of water. What is the distance between car and atone at the instant when particle reaches at point B ?

In the figure there is a long horizontal bridge over a river 75 m high from water surface. A strong man throws a stone in the parallel plane of the bridge. A observer in a car travelling on the bridge finds the stone going pass by the car while ascending and also while descending between two points on the road 30 m away. The car is travelling at a speed of 15 m/s. The stone is thrown from the bank of river just at the same level of water. Horizontal distance AB travelled by stone is :-

The small dense stars rotate about their common centre of mass as a binary system, each with a period of 1 year. One star has mass double than that of the other, while mass of the lighter star is one-third the mass of the Sun. The distance between the two stars is r and the distance of the earth from the Sun is R , find the relation between r and R .

The change in the value of g at a height h above the surface of the earth is the same as at a depth d below the surface of earth. When both d and h are much smaller than the radius of earth, then which one of the following is correct?