Gravitational Field (CIE A Level Physics)

Fig. 1.1 shows a small horizontal region on the surface of the Earth. X is a point underneath the surface which contains material of higher density than the material surrounding it.

On Fig. 1.1, draw the gravitational field lines on the surface of the Earth. 

Fig. 1.1

The spacecraft Centurion leaves Earth for Venus to identify potential mining locations based on fluctuations in the gravitational field strength on the surface of Venus.

The Centurion sends a landing party to the surface in a shuttle. The shuttle has a mass of 3.24×10⁷ kg when launched from the Centurion, but looses 5% of its total mass in fuel combustion due to landing. The shuttle has a weight of 270 MN when it comes to rest on the surface of Venus.

Calculate the gravitational field strength on the surface of Venus.

The landing crew collect rock samples from the landing site. When the landing crew has finished its mission, the shuttle launches to return to the Centurion. At an altitude of 250 km above the surface of Venus, the mass lost through fuel combustion is equal to the total mass of the rocks collected at the surface.

Gravitational force is inversely proportional to the square of the distance between masses.

Calculate the gravitational field strength of Venus at 250 km above the surface.

The radius of Venus is 6.3 × 10⁶ m.

An equation to describe field strength is:

Define X and Y in the equation above.

Based on your answer to part (a), define the terms in the following equation:

The following text is about gravitational fields.

Complete the following sentences by crossing out the incorrect words: 

A gravitational field is a region of space in which objects with mass / charge will experience a force.

The direction of the gravitational field is always directed away from / towards the centre of the mass.

Gravitational forces are always / never repulsive.

Gravitational fields around a point mass are uniform / radial.