Question 6 [35 marks] a) A plane flies at 550 km/hr into a headwind of 50 km/hr at 60 with the direction of the plane as shown. (10 marks) Wind 50 km/hr 60 What is the actual speed to the plane as a result of this headwind? b) A mass oscillates up and down at the end of a spring. The length of the spring L (in centimetres) after time t (in seconds) is given by the following equation: L =12+6cos 2nt Calculate the length of the spring after 2 seconds. (10 marks) c) The diagram shows a circle with centre O and radius 42 cm. A and B are points on the circumference such that arc AB an angle of 125 as shown. O 1250 A i) Calculate the length of arc AB. Use angle 0 in radians. (5 marks) (Give your answer to 4 significant figures) ii) Find the area of the sector AOB (shaded area). (10 marks) (Give your answer to 6 significant figures)