Question

The variation of velocity of a particle moving along a straight line is shown in the figure. The magnitude of displacement of the particle in 4 s is :

• A. 25 m
• B. 30 m
• C. 55 m
• D. 60 m

Answer 1

Answer: (C)

55 m

Displacement from a velocity time graph is obtained as the area under the curve.
Between t = 0 s and 1 s:
$A_1=\frac{1}{2}\times 20\times 1=10m$
Between t= 1 s and 2 s:
$A_2=1\times 20=20m$
Between t = 2 s and 3 s:
$A_3=\frac{1}{2}\times 1\times 10+10\times 1=15m$
Between t = 3 s and 4 s:
$A_4=10\times 1=10m$
Hence total area under graph = $55m$
Hence option C is correct.