The following 3 graphs present the displacement during a 30 second flight of a helicopter: 45 40 35 30 25 9 0 0 20 Displacement above ground (m) 15 10 .... 5 O 0 10 20 30 40 50 60 70 Displacement along ground (m) 70 60 ... . 50 40 Displacement along ground (m) 30 20 .. . .. ... 10 . 0 5 10 15 20 25 30 35 Time (s)\f(a) (b) (c) In your answer book, sketch a graph of the velocity along the ground vs time and velocity above the ground vs time. (10 marks) Using the information available in the above figures, and the graphs you made in part (a) of this question, answer the following: i) the maximum altitude reached by the helicopter; (2 marks) ii) the approximate time when the helicopter has the greatest velocity along the ground; (2 marks) iii) the approximate maximum velocity of the helicopter travelling towards the ground; (4 marks) iv) the direction in which the helicopter has the greatest acceleration. (2 marks) 20 seconds after a skydiver jumped from the helicopter their displacement can be modelled by the following vector: (Ut)i+(Vi-r*)j where U and V are the initial velocities and ris the time. Considenng horizontal and vertical motion independently, it can also be expressed by the functions: x(t)=Ut y(t)=vi-7 d(cosx| sinx dx Use these equations to find the skydiver's acceleration at this time. (10 marks)