Question 1 (13 Marks) wall a. The graph below shows the side view of a section of a skate park that is proposed to be built near an existing wall. A linear ramp (AB) is constructed from a triangular prism 20 metres deep. The equation x 1 used to model the linear ramp is y , where y is the height above the ground in metres and x is the 10 5 horizontal distance from the wall in metres. B A C D E i. How far from the wall does the linear ramp (AB) begin? ______________________________________________________________________________________ ______________________________________________________________________________________ 1 mark ii. The point C is vertically below point B. If C is 25 m from A, how high is point B above the ground? ______________________________________________________________________________________ ______________________________________________________________________________________ 2 marks iii.What is the distance from A to B? Express your answer correct to two decimal places. ______________________________________________________________________________________ ______________________________________________________________________________________ ______________________________________________________________________________________ ______________________________________________________________________________________ 2 marks iv. If concrete weighs 1.8 tonnes per m3, how much does the concrete ramp weigh? ______________________________________________________________________________________ ______________________________________________________________________________________ ______________________________________________________________________________________ ______________________________________________________________________________________ 2 marks b. The skaters half-pipe (BD) consists of a symmetrical curved timber floor attached to the ramp at B. The bowl ends at point D. The distance between B and D is 30 metres. The lowest point of the curve is .5 metres from the ground. i. Give the coordinates of point D ______________________________________________________________________________________ ______________________________________________________________________________________ 1 mark ii. Give the coordinates of point E ______________________________________________________________________________________ ______________________________________________________________________________________ 1 mark iii. The equation used to model the bowl is y a x b c . Find the values of a, b and c. 2 ______________________________________________________________________________________ ______________________________________________________________________________________ ______________________________________________________________________________________ ______________________________________________________________________________________ 2 marks iv. Show that y 2 x 2 56 x 809 is another equation that can be used to model the shape of the bowl. 225 75 50 ______________________________________________________________________________________ ______________________________________________________________________________________ ______________________________________________________________________________________ ______________________________________________________________________________________ ______________________________________________________________________________________ ______________________________________________________________________________________ 2 marks Question 2 (12 marks) A roller coaster track is in the shape of a cubic function (side view). The y-axis represents the height above the ground and the x-axis the horizontal distance, which is at ground level. For all questions, only consider the section 0 x 110. All measurements are in metres (m). Scales are shown in the grid below. a. If the equation is in the form of y ax b x c , use the information in the graph to determine the values of b and c. 2 ______________________________________________________________________________________ ______________________________________________________________________________________ ______________________________________________________________________________________ ______________________________________________________________________________________ 2 marks b. The roller coaster passes through the point (60, 20). Hence, determine the exact value of a. ______________________________________________________________________________________ ______________________________________________________________________________________ ______________________________________________________________________________________ ______________________________________________________________________________________ 2 marks c. Determine the starting height of the roller coaster (correct to two decimal places) ______________________________________________________________________________________ ______________________________________________________________________________________ ______________________________________________________________________________________ 2 marks d. The engineers decide to move the roller coaster track vertically down by 5 metres to add an underground tunnel to the roller coaster. Give the new equation of the curve. Write in the form 𝑦 = 𝑎𝑥 3 + 𝑏𝑥 2 + 𝑐𝑥 + 𝑑. ______________________________________________________________________________________ ______________________________________________________________________________________ ______________________________________________________________________________________ ______________________________________________________________________________________ 2 marks e. Sketch the new track in the original grid of previous page labelling the x-intercepts only (correct to 2 decimal places). Give the new domain assuming the ride ends at ground level (y = 0). ______________________________________________________________________________________ ______________________________________________________________________________________ ______________________________________________________________________________________ ______________________________________________________________________________________ 3 marks f. Determine the horizontal distance-part that is underground. Give correct to 2 decimal places. ______________________________________________________________________________________ ______________________________________________________________________________________ 1 mark