Speed time graph of two cars `A` and `B` approaching towards each other is shown in figure. Initial distance between them is `60m`. The two cars will cross each other after `t` seconds. Find value of `t`.

Answer

C

Explanation

Slope of v-t graph gives acceleration /retardation
` |a|=5m//s^(2) ` for both of them . A has acceleration while B has retardation
` |S_A|+|S_B|=60 " "or " "{(1)/(2) xx 5xx t^(2)} +{20 t -(1)/(2) xx 5xx t^(2)}= 60 or t= 3s `