question_answer

 A life is going up. The variation in the speed  of  the lift is as given in the graph What is the height to which the lift takes the passengers ?

A)  3.6m                                    

B)  28.8m

C)  36.0m                                  

D)  40.0m

Correct Answer: C

Solution :

The area covered between the velocity-time graph and time, axis gives the displacement. Area of  \[\Delta ABC=\frac{1}{2}\times AC\times BC\]                 \[=\frac{1}{2}\times 2\times 3.6=3.6\] Area of \[\square BCDE=BD\times BC\]                                 \[=8\times 3.6=28.8\] Area of \[\Delta DEF=\frac{1}{2}EF\times DE\]                 \[=\frac{1}{2}\times 2\times 3.6\]                 \[=3.6\] \[\therefore \] Total area \[=3.6+28.8+3.6=36m\]