Question 3. (6 marks) A stone is thrown from the top of a sea cliff at 12 m s at an angle of 20 below the horizontal. Sea a. Write a vector equation which gives the position of the ball as a function of time. Include the given values in your equation. (2) b. Clearly indicate the coordinate system that you used in (a) on a diagram of the ball's trajectory. (Make sure that you put the origin in the correct place.) (1) c. The stone reaches the sea below 1.8 s after it is thrown. Find the height of the cliff. (3) [6] Question 7. (8 marks) Provide explanations for the following: a. The Sun has exerted a force of about 3 x 1022 N on the Earth for over 4 billion years. Yet the Earth has not moved closer to the Sun. Explain (i) why this is so and (ii) whether the force of the Sun has any effect on the Earth's motion. (3)