1.1. Place a tick (✓) next to the equation in Table 1.1 which represents the gravitational potential energy of two point masses m and M separated by a distance r. 

Table 1.1 

1.2. The diagram in Fig. 1.2 shows two satellites m₁ and m₂ in orbit around the moon. 

Fig. 1.2

Satellite m₁ is in orbit at a distance of r₁ from the centre of the moon and satellite m₂ is in orbit at a distance of r₂ from the centre of the moon. 

State which of the satellites has the higher gravitational potential energy. 

1.3. Satellite m₁ has a mass of 300 kg and orbits above the centre of the moon at a radius r₁ of 500 m.

The mass of the moon is 7 × 10²² kg.

Calculate the gravitational potential energy of the satellite in this position. Newton's gravitational constant, G = 6.67 × 10⁻¹¹ N m² kg⁻²

1.4. State why the equation for gravitational potential energy in (a) has a negative sign and why your answer to (c) is negative.