Question

b) The velocity of changes from 18 km/h to 72 km/h in 30 s. Calculate change in velocity in m/s.​

Answer 1

Explanation:

Acceleration ( over an interval of time ) = (change in velocity )/ (time taken for the change to happen ).

A = (v2 - v1)/∆t

Here v2 = 72kmph =new velocity and v1 = 18kmph = initial velocity (just before transition) and ∆t = time taken in transition = 30 sec. = 30 /60 min. = 1/2 min. =1/(2×60) hrs.= 1/120 hrs.

All data according to the question.

So , A= (72 - 18) / (1/120) = 54 ×120 = 6480 kmphour squared.