Question

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

Answer 1

Explanation:

Here, Initial speed, uu = 20 km/h

 =20×1000 m60×60 s=20×1000 m60×60 s

 =5.55m/s =5.55m/s …(1)

Final speed, vv= 60 km/h

 =60×1000 m60×60 s=60×1000 m60×60 s

  = 16.66 m/s  …(2)

Acceleration, aa = ? (To be calculated)

And,   Time, tt = 6 s

We know that :  v=u+atv=u+at

So,   16.66=5.55+a×6a×6

 6a=16.66−5.556a=16.66-5.55

 6a=11.116a=11.11

 a=11.116a=11.116

Thus, Acceleration, aa = 1.85 m/s2s2.

Answer 2

Answer:

20 km/h  = 20 x 1000 /60 x 60

60 km/h  = 60 x 1000 /60 x 60

Using v = u+ at

600/36 - 200/36 = 6a

400/216

= 1.85 m/s2