Question

brakes are applied to a car produce uniform retardation of 0.9m/s² if the car was traveling with velocity of 27m/s what is distance covered before coming to rest.​

Answer 1

Acceleration = -0.9m/s²

u = 27m/s

since brakes are applied,

v = 0m/s

Applying equation:-

v²=u²+2as

we get,

0=27² + 2×(-0.9)s

0= 729 -1.8s

-729 = -1.8s

so,

s = -729/-1.8

s = 405

So, the distance covered by car before coming to rest was 405m.

Cheers!

Answer 2

$\textbf{\underline{\underline{According\:to\:the\:Question}}}$

→Uniform retardation = 90cm/s²

a = - 0.9 m/s²

u = 27 m/s

v = 0m/s

→To Find :-

s = ?

${\boxed{Equation\:\:of\:\:Motion}}$

v² = u² + 2as

2as = v² - u²

$\tt{\rightarrow s = \dfrac{v^{2}-u^{2}}{2a}}$

$\tt{\rightarrow s =\dfrac{(0)^{2} - (27)^{2}}{2\times (-0.9)}}$

$\tt{\rightarrow s = \dfrac{-27\times 27}{-2\times 0.9}}$

s = 405m

$\boxed{\begin{minipage}{9 cm} Additional Information \\ \\ \ Distance = Speed\times Time \\ \\ Displacement=Velocity\times time \\ \\ Average\; Speed = \dfrac{Initial\:\:Speed+Final\:\:Speed}{2} \end{minipage}}$