Question

A bus decrease its speed from 90km/h to 54km/h in 5 Dec Find acceleration and distance travelled in the duration

Answer 1

acceleration =v-u/t
v= 90km/h=25m/s
u=54km/h=15m/s
t=5sec
thus, 25-15/5=2m/s^2

Answer 2

given:-v=54km/h =15 m/s
           u=90km/h =25 m/s
           t=5sec
 by using the equation v=u+at
                                 => 15=25+a(5)
                                 =>  15=25+5a
                                 => 15-25=5a
                                 => -10=5a 
                                 =>5a=-10
                                 =>a=-10/5
                                 =>a= -2m/s^2(since the speed is retarding or decreasing)