Velocity-time Graph

As taught in NCERT Class 11, Chapter 3 (Motion in a Straight Line), the area under a velocity-time graph equals the displacement of the body. For uniformly increasing velocity, the graph is a straight line forming a trapezium with the time axis. The area of this trapezium is the average of the two parallel velocity values times the time interval: distance = ((5 + 25)/2) × 4 = 15 × 4 = 60 m. The option 100 m wrongly uses the final velocity 25 m/s times 4 s, ignoring that velocity was lower earlier. The option 40 m uses only the initial velocity contribution incorrectly. The option 80 m results from using a wrong average of 20 m/s. Plausibility check: the constant acceleration is (25−5)/4 = 5 m/s², and substituting into s = ut + (1/2)at² gives 5×4 + (1/2)(5)(16) = 20 + 40 = 60 m, exactly matching the graphical area and confirming the result.