Question

a car traveling at a speed of 20m/s applies brakes and stops within 10s.what is the acceleration of the car

Answer 1

u=20m/s
v=0
t=10s

a=(v-u) /t
a=(0-20)/10
a=-20/10
a=-2m/s²

Answer 2

initial velocity ,u is 20 m/sec and final velocity ,v is 0 and time ,t = 10 sec. thus here we will apply first equation of motion that is v=u+at. 0= 20+ax10. -10a= 20. a=20/-10. and a=-2. hence acceleration is -2 m/ sec sq.