Respuesta :

Answer:

1200m/s

Explanation:

initial velocity=72km/h=20m/s

Final velocity=40m/s

Distance=0.5m

Now,

2as=v^2-u^2

or,2*a*0.5=40^2-20^2

or,1a=1200

or,a=1200/1

therefore,acceleration=1200m/s

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