Question

find the Initial velocity of a car which is stopped in 20sec by applying brakes. the retardation due to brakes is 1.5m /s²

Answer 1

1st equation of kinematics:
v=u+at

as per question...
v=0m/sec {as body comes to rest} =final velocity
a=-1.5m/s^2=retardation
t=20sec=time
u=??=initial velocity

so.....
v=u+at
=>0=u+(-1.5)(20)
=>-u=-1.5×20
=>u=30m/s

hope it helps you...
☺☺

Answer 2

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Thank you for Question♥
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Solut¡On:

v=0
u=?
t=20sec
a=1.5ms^-2

Formulae:

v=u+at

u+at=0

u+1.5×20=0

u+30=0

initial velocity=30m/s

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