QUESTION 1 a) Complete the SI unit for each quantity in Table 1 : Base quantity SI unit Length Mass Time Electric current Table 1 (2 marks) b) Convert 850 42 into SI units. Give your answer with the correct number of significant figures. (Given 1lb = 0.454 kg, Ift = 0.3048m ) (2 marks) c) A stretched wire of length, / and cross-sectional area, A extends by an amount of x. The elastic energy, W stored in the wire is given by the equation below; (Hint: W = Force x displacement) EAx2 W = 21 Determine the dimensional expression for E (5 marks) d) Yusuf throws a ball vertically upwards and catches the ball after 10 s. Sketch the velocity-time graph for the situation. (Neglect air resistance) (3 marks) e) An object is thrown vertically upwards from the roof of a building at a speed of 20 m/s. The object reaches the ground after 8.0 s. Determine the height of the building