Question

Car travelling at 60 km per hour on applying brakes stopped in 10 second calculate its acceleration

Answer 1

hey dear
here is your answer

given data :

initial velocity = 60 km/hr or 16.67 m/s

final velocity = 0

time taken = 10 seconds

to find : acceleration

solution :

by using 1st equation of motion

v = u+at

0 = 16.67+10a

10a = -16.67

a = -1.667 m/s^2

hope it helps :)

Answer 2

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

★Note :-

Here in question km is very big unit for describing acceleration of car so we have to convert it into m/s.

★Given:-

u = 60 km/h

v = 0m/s (As because car stops)

t = 10 seconds

★Solution :-

★Convert t into m/s

$\tt{\rightarrow\dfrac{60\times 1km}{1h}}$

$\tt{\rightarrow\dfrac{60\times 1000m}{3600s}}$

$\tt{\rightarrow\dfrac{600}{36}}$

= 16.67 m/s

★Now

${\boxed{\sf\:{Acceleration}}}$

$\tt{\rightarrow a = \dfrac{v-u}{t}}$

$\tt{\rightarrow\dfrac{0-16.67}{10\;second}}$

$\tt{\rightarrow\dfrac{-16.67}{10\;second}}$

= - 1.67 m/s²

$\text{Note :Here\; negative\; sign\; shows\; that \;car\; is \;under\; retardation. }$

★Hence

${\boxed{\sf\:{Retardation\;of\;car = 1.67m/s^{2}}}}$

$\boxed{\begin{minipage}{11 cm} Additional Information \\ \\ \ Distance = Speed\times Time \\ \\ Displacement=Velocity\times time \\ \\ Average\; Speed = \dfrac{Initial\:\:Speed+Final\:\:Speed}{2} \end{minipage}}$