Question

bus decreases its speed from 80 kilometre per hour to 60 km per hour in 5 second find acceleration of bus

Answer 1

initial velocity = 80km/h
                        =80*1000/60*60
                         =200/9m/s
final velocity=60km/h
                   =60*1000/60*60=50/3
  time=5s
therefore acceleration=v-u/t
                                    =[200/9-50/3]÷5
                                    =1.111111.....m/s↑2

Answer 2

$\large\sf{u=80km/h=\frac{80×1000}{3600}m/s=\frac{200}{9}m/s}$

$\large\sf{v=60km/h=\frac{60×1000}{3600}m/s=\frac{150}{9}m/s}$

$\large\sf{Time(t)=5s}$

⠀⠀

$\therefore$$\large\sf{Acceleration(a)=?}$

⠀⠀⠀

$\huge\sf{We\:know\:that,v=u+at}$

$\longrightarrow$$\large\sf{a=\frac{v-u}{t}=\frac{( \frac{150}{9} - \frac{200}{9} ) }{5} }$

$\longrightarrow$$\large\sf{\frac{-\frac{50}{9} }{5} }$

$\longrightarrow$$\large\sf{-\frac{10}{9}}$

$\longrightarrow$$\large\sf{1.1m/s}$