Question

a car travelling at a uniform velocity of 60 km per hour it hours in 10 seconds and reaches city of 45 km per hour find its retardation​

Answer 1

Firstly convert 60km/ hr in m/sec then it comes to 50/3 them similarly we get 40 km/hr as 25/3 so while putting in the formula v-u/t we get our answer as 0.42 m/sec²

Answer 2

u (initial velocity)= 60 km/h or 60×5/18= 16.666..m/s or 16.7 m/s or 17 m/s

t (time)= 10 s

v (final velocity)= 45 km/h or 45×5/18= 12.5 m/s or 13 m/s

retardation= v-u/t

= 13 m/s- 17 m/s /10 s

= 4 m/s /10 s

= 0.4 m/s^2 (ans)

I have rounded off the numbers to whole numbers but if you want you can also do with decimals to tenth places.