For the following velocity-time graph, the average speed for the motion during first 80 ~s is

Step-by-step solution

As we know that, Distance = Area under velocity - Time graph Total distance travelled in 80 ~s = Area of O A B+ Area of B C D aligned & = | 1 2 (A E O B) |+ | 1 2 (C F B D) | & = | 1 2 10 40 |+ | 1 2 -10 40 | & =200+200=400 ~m aligned Total time taken, t=80 ~s aligned Now, the average speed & = Total distance Total time taken & = 400 80 =5 ~m / s aligned