Question

a car initially at rest move with the constant accerates along straght line read after it's spread increase and finally related uniformly. the time interval for the three parts of the jounry are in the ratio 1:3:1 find average velocity ?​

Answer 1

32km per hour

Step-by-step explanation:

Step-by-step explanation:

In first case v = a t

==> a t = 40 km p h

Now distance covered S1 + S2 + S3

S1 = 1/2 a t^2 and S3 = 1/2 a t^2

But S2 = 3t * 40 = 120 t km

Hence total distance = at^2 + 120 t

Time taken (total) = t + 3t + t = 5 t

Hence average speed = at^2 + 120 t / 5 t

Cancelling t we have at + 120 / 5 = 40 + 120 / 5 = 160/5 = 32 km per hour