Show that converting a speed of x metres per second into kilometres per hour gives 3.6x km/h. Then a car travels at 25 m/s. Without using a calculator, use your result to find its speed in km/h and determine whether it exceeds 90 km/h.
(a)Show that converting x m/s into km/h gives 3.6x km/h.(3)
(b)Use the result to find the speed of the car in km/h and state whether it exceeds 90 km/h.(4)
(Total for Question 9 is 7 marks)