Question

For the velocity-time curve shown, the distance covered by a body form 5th to 7th second of its motion is _____ fraction of the total distance covered by it.

• A. $4/15$
• B. $9/2$
• C. $1/2$
• D. $2/3$

Answer 1

Answer: (A)

$4/15$

Slope of BE $=\frac{0-2}{8-5}=\frac{-2}{3}$

$\therefore$ $\frac{0-v{|}_c}{8-7}=\frac{-2}{3}$ $⟹v{|}_c=\frac{2}{3}$

Total distance covered $D_T=$ Area (OABE) $=\frac{1}{2}\times (2+8)\times 2=10$ m

Distance covered in $5<t<7$ s, $D^{\prime }=\frac{1}{2}\times (2+\frac{2}{3})\times 2=\frac{8}{3}$ m

$⟹$ $\frac{D^{\prime }}{D}=\frac{\frac{8}{3}}{10}=\frac{4}{15}$ m