Concept:The area under a velocity-time graph gives displacement, while the total area without sign gives distance travelled.
Explanation:From the graph, divide the area into four regions from
t=0 to
t=10 s.
Region 1 (0 to 2 s): rectangle of height
8 and width
2A1=8×2=16 m (above axis, positive)
Region 2 (2 to 4 s): rectangle of height
−4 and width
2A2=−4×2=−8 m (below axis, negative)
Region 3 (4 to 8 s): rectangle of height
4 and width
4A3=4×4=16 m (above axis, positive)
Region 4 (8 to 10 s): rectangle of height
−4 and width
2A4=−4×2=−8 m (below axis, negative)
Displacement = sum of signed areas:
16−8+16−8=16 m
Distance = sum of magnitudes of areas:
16+8+16+8=48 m
Required ratio:
Displacement:Distance=16:48=1:3Answer:D.
1:3