For the velocity-time graph shown in the figure below, the distance covered by the body in the last two seconds of its motion is what fraction of the total distance covered by it in all seven seconds.

Explanation

Step 1: understand the graph. The graph is a trapezoid showing velocity over time, with key points at t=0, v=0; t=3,v=10m/s; constant v=10m/s from t=3 and v=0 at t=7. Step 2: calculate total distance covered in 7 seconds. The total distance is the area under the graph, divided into a triangle(0-3s), a rectangle (3-5s), and another triangle (5-7s). The total distance = ½ x 3 x10 +2 m. Step 3: calculate the distance covered in the last two seconds: the distance in the last 2 seconds = area of the second triangle= ½ x 2 x10= 10m. Step 4: calculate the fraction; (distance covered in last 2 seconds) /total distance = 10/45=2/9= 0.222 which is closest to 1/4 =0.25 .