Question

Given below is a graph between a variable force $(F)$ (along $y$-axis) and the displacement $(x)$ (along $x$-axis) of a particle in one dimension. The work done by the force in the displacement interval between $0m$ and $30m$ is

• A. 275 J
• B. 375 J
• C. 400 J
• D. 300 J

Answer 1

Answer: (B)

Work done $=$ area of $F$-t graph with x-axis
Total area = area of $\Delta ABC$
$+$ area of $\Delta BCDE+$ area of $\Delta ELJE+$
area of $\Delta FGH$ Area of $\Delta ABC=\frac{1}{2}\times 5\times 10=25J$
Area of $\Delta BCDE=10\times 10=100J$
Area of $\Delta EUG=5\times 30=150J$
Area of $\Delta FGH=\frac{1}{2}\times 10\times 20=100J$
$\therefore$ Total area $=25+100+150+100=375J$