Question

the velocity of car changes from 18 km/hr to 72 km /hr in 30s what will be its acceleration in km/h² and in m/s²​

Answer 1

Answer:

* 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.

Answer 2

Answer:

Acceleration = 0.5m/s²

Explanation:

velocity (V1) = 18km/h

velocity (V2) = 72km/h

change in velocity (ΔV) = V2 - V1

change in velocity (ΔV) = (72 - 18)km/h

change in velocity (ΔV) = 54km/h

change in velocity (ΔV) = 15m/s

time (t) = 30 s

Acceleration (a) = ΔV/t

Acceleration (a) = 15/30

Acceleration (a) = 0.5m/s²