The velocity time graphs of two bodies `A` and `B` are shown in Figure. Observe these graphs carefully and answer the following questions :
(i) From the shape of graphs, what is nature of motion of `A` and `B`
(ii) What do you infer from the slopes of the graphs ?
(iii) What are the initial velocities of `A` and `B` ?
(iv) What is acceleration of `A` ?
(v) What is acceleration of `B` ?
(vi) What distance is travelled by `B` before coming to rest ?
(vii) At what time will the two bodies have equal velocity ?

Explanation

(i) As vel-time graph of `A and B` are straight lines, both the bodies have uniformly acclerated motion.
(ii) Slope of A is positive. So acceleration of `A` is positive. Slope of `B` is negative. So acceleration of `B` is negative, i.e., `B` moves with retardation.
(iii) Initial vel. of `A = 0`. Initial vel. of `B = 30 m//s`
Ac c. of A `= ("change of vel.")/("time taken") = (20 - 0)/(15) = 1.33 m//s^(2)`
(v) Ac c. of B `= ("Change of vel.")/("time taken") = (0 - 30)/(10) = -3 m//s^(2)` Negative sign indicates retardation
(vi) distance travelled = Area under vel.time graph of `B = (30 xx 10)/(2) = 150 m`
(vii) From the graph, velocity of A = vel. of B at `t = OK`, whose value can be read from the scale on the graph.