question_answer

The variation of velocity of a particle with time moving along a straight line is illustrated in the following figure. The distance travelled by the particle in four seconds is      [NCERT 1973]

A)             60 \[m\]

B)             55 \[m\]

C)             25 \[m\]

D)             30 \[m\]

Correct Answer: B

Solution :

                Distance = Area under v ­? t graph\[={{A}_{1}}+{{A}_{2}}+{{A}_{3}}+{{A}_{4}}\]             \[=\frac{1}{2}\times 1\times 20+(20\times 1)+\frac{1}{2}(20+10)\times 1+(10\times 1)\]             \[=10+20+15+10=55\ m\]