Question

pls answer immediately​

Answer 1

Answer:

u=72km/h =72×1000÷3600=20m/s

v =0 (applied brake)

s=10m(distance)

Now using (v²=u²+2as)

(0)²=(20)²+2(-a) ×10 (-a becz retardation takes place)

0=400-20a

0-400=-20a

-400=20a=-400÷20=20

so retardation will be 20m/s....