Question

A bus decreases its speed from 72 kilometre to 36 km in 1 min 40 sec find the acceleration of the bus​

Answer 1

Answer:

You have to start by converting either the seconds to hours or the hours to seconds likewise with the Km. Since I have always done it in meters per second squared that’s what I’ll do it here in one step.

72Km/hr * (1,000m/1km) * (1hr/60min) * (1min/60sec) = 20m/s. (You set this up this way so that the Km, hrs, and min all cancel leaving you with m/s.)

Then you do the exact same thing for the 36Km/hr which will give you 10m/s (just put the 36 in where the 72 is).

Givin’ the knowns of initial velocity (Vi) final velocity (Vf) and time (t) you would use the equation (Vf - Vi) / t = a. So, given Vf = 10m/s a Vi = 20m/s and a t = 5s you plug it in. (10m/s - 20m/s) / 5s = -2.0m/s^2.

It is negative because they are slowing down also it is 2 because you have one significant digit.