Question

A bus decreases its speed from 80kmh-1 to 60kmh-1 in 5sec. find the acceleration of the bus.

Answer 1

Here...the velocity changes from 80 km/h to 60 km/h....

So the initial velocity is 80 km/h and the final velocity is 60 km/h....

The SI unit of velocity is m/s....so first we should convert into m/s...

So multiply the 80 km/h and 60km/h with 5/18...

So... a = v-u/t

= 60 x 5/18 - 80 x 5/18

= 50/3 - 200/9

= 150/9 - 200/9

= -50/45

= -10/9 m/s...

Hope u understand... :)

Answer 2

Hey friend here is your answer!!!!!☺️☺️☺️

acceleration (a) = final velocity (v) - initial velocity (u) / time (t)

Here bus is decreasing it's speed so there would be retardation. So the acceleration would come in minus

here v = 60km/h
u = 80km/h
t = 5 seconds = 5/3600 hours

a = v - u /t
= -20×3600/5
= -4×3600
= -14400 km/h^2
☺️☺️hope it helps ☺️☺️