Question

A driver applied the break and slow down the velocity of the bus frim 80kmper/hrbto 60kmper/5sec . Calculate the acceleration of the bus

Answer 1

u= 80km/HR

= 80*5/18

=22.22m/s

v=60km/hr

=60*5/18

=16.66m/s

t=5 sec

a=v-u/t

=16.66-22.22/5

= 12.216 m/s2

Answer 2

The car traveled 50 m while accelerating from 0 to 20 m/s in 5 seconds.

The distance d is from

d = v(avg) • t

where v(avg) is the average velocity during the time, or

v(avg) = v(initial) + ∆v/2.

Here v(initial) is 0 and ∆v is 20 m/s, so

v(avg) = 20 m/s / 2 = 10 m/s.

d = 10 m/s • 5 s = 50 m.