Question

A car is travelling at 20 km/h, it speeds up to 60 km/h in 6 seconds. What is its acceleration?

Answer 1

u = 20km/h = 20×5/18 = 10 × 5/9 =50/9 m/s

v = 60km/h = 60×5/18 =50/3m/s

t = 6 sec

a = ?

using first equation of motion ,

v=u+at

50/3 = 50/9 + 6×a

50/3 - 50/9 = 6a

150/9 - 50/9 = 6a

100/9 = 6a

100/9 × 6 = a

100/54 = a

50 / 27 = a

1.85 m/s^2 = a.