How do i answer this maths question?

linleo2007

A car is travelling due east along a straight road when it passes a point P. The Acceleration of the car during the next 7 seconds is modelled in the acceleration time graph above, where a ms-2is the acceleration of the car due east and t secondsis the time after passing the point P.i. Explain why the speed of the car is greatest when t = 6. [1]The speed of the car when it passes P is 12 ms-1.ii. Calculate the speed of the car when t = 3. [3]iii. Show that, when t = 5, the speed of the car is 25 ms-1. [3]iv. Show that, for 5 ≤ t ≤ 7, the acceleration is given by a = -5t + 30. [2]v. Explain how the graph may be used to show that the speeds at t = 5 and t = 7are equal.

Reply 1

Ferret!

Area under acceleration-time graphs represent velocity. If graph (which you should post, along with your attempt) consists of shapes like rectangles and trapeziums then just find the area under the graph within the times required by using area formulæ.