Here, Initial speed, `u` = 20 km/h
`" " =(20xx1000" m") /(60xx60" s")`
`" "= 5.5 m//s" "` …(1)
Final speed, `v`= 50 km/h
`" "=(50xx1000" m")/(60xx60" s")`
`" "` = 13.8 m/s `" "`…(2)
Acceleration, `a` = ? (To be calculated)
And, `" "` Time, `t` = 10 s
Now, `" " v=u+at`
So, `" "13.8= 5.5 +axx10`
`" "10a=13.8 - 5.5`
`" "10a= 8.3`
`" "a=(8.3)/(10)`
`" "a= 0.83 m//s^(2)`
Thus, the acceleration is 0.83 m/`s^(2)`. The correct answer is (d)