question_answer 21)

Figure 3.91 gives the x-t plot of a particle in one-dimensional motion. Three different equal intervals of time are shown. In which interval is the average speed greatest, and in which is it the least ? Give the sign of average velocity for each interval.   Fig. 3.91  

Answer:

Slope of x-t graph in a small time interval = Average speed in that interval As the slope of x-t is greatest in interval 3 and least in interval 1, so the average speed is greatest in interval 3 and least in interval 1. As the slope of x-t is positive in intervals 1 and 2 and negative in interval 3, so average velocity is positive in intervals 1 and 2 and negative in interval 3.