Question

A car is initially at rest on a straight road. The graph shows the speed of the car as a function of time.

12 10 9 4 2 0 0 1 2 34 6 7 8 9 10 11 12 13 14 t (s)

What is the speed of the car at t=7 s?
How much distance did the car cover in the first 8 seconds?
Determine the distance covered by the car between t=8 s and t=13 s?
What is the average speed of the car between t=4 s and t=7 s?

Answer 1

A) According to the graph we can see the velocity corresponding to t=7s is 7m/s therefore velocity at t=7m/s.

The distance covered by the car can be calculated by the area under v-t graph.

B) For the first 8 seconds, distance can be calculated by calculating area from time 0 to A

C) For time t=8 to 13 s distance is given by area under C to D.

D) Average speed = total distance/ total time . Therefore we first calculate the total distance by area under t=4 to 7s then we divide it by total time i.e. 3s .