Question

A car initially at rest ir picks up a velocity of 72km per hour over a distance of 25m find acceleration

Answer 1

We can use the formula : v*2-u*2=2as

Here in this question ,as the car is initially at rest, therefore u=0

and also it is given in question that v=72km/hr

v=72×5÷18m/sec(whenever you wanna convert km/hr in to m/sec ...directly multiply the value in km/hr with 5÷18)

v=20m/s

Now using the above mentioned formula:

v*2-u*2=2as

20*2-0=2×a×25

20×20=50×a

400÷50=a

or. a=8m/sec*2

Answer 2

Using equation of above image,
where,
V = final velocity = 72 km/h
Vo = initial velocity = 0 km/h
d = 25 m = 0.025 km
a = acceleration

Substituting all values in above equation then we get,

5184 - 0 = 2(a)(0.025)
a = 103680 km per second square

"Thanks"