question -29 , 30 , 31 , 32 gravitational , electric and magnetic field .

(18 marks) 29. The earth has a mass of 5.98 x 10" kg and the moon has a mass of 7.35 x 10"kg. The distance from the centre of the moon to the centre of the earth is 3.84 x 10 m. A rocket with a total mass of 1200 kg is 3.0 x 10" m from the centre of the earth and directly in between the earth and the moon. Find the net gravitational force on the rocket from the earth and moon. (4 marks) 30. A 12 kg meteor experiences an acceleration of 7.2 m/s , when falling towards the earth. a) How high above the earth's surface is the meteor? (3 marks) b) What force will a 30 kg meteor experience at the same altitude? (2 marks) 31. A 500 kg satellite experiences a gravitational force of 3000 N, while moving in a circular orbit around the earth. a) Find the radius of the circular orbit. (2 marks) b) Find the speed of the satellite. (2 marks) c) Find the period of the orbit. (2 marks) 32. To simulate gravity, a circular space station with a radius of 150 m is rotated so that astronauts standing on the inner surface move at 30 m/s. If the 75 kg astronaut stands on a bathroom scale, what reading will it give? (Assume that the scale is calibrated in newtons.)