Question

a car is moving uniform on a road it is acceleration of 2m/s^2 . as a result it covers a distance of 120 meters in nine seconds. The initial and final velocities of the car are

Answer 1

Answer:-

• Acceleration=a=2m/s^2
• Distance=s=120m
• Time=t=9s
• Initial velocity=u=?
• Final velocity=v=?

According to second equation of motion

$\boxed{\sf s=ut+\dfrac{1}{2}at^2}$

$\\ \sf\hookrightarrow 120=9u+\dfrac{1}{2}\times 2\times 9$

$\\ \sf\hookrightarrow 120=9u+9$

$\\ \sf\hookrightarrow 120=9(u+1)$

$\\ \sf\hookrightarrow u+1=\dfrac{120}{9}$

$\\ \sf\hookrightarrow u+1=13.3$

$\\ \sf\hookrightarrow u=13.3-1$

$\\ \sf\hookrightarrow u=12.3m/s$

Now

According to First equation of motion

$\boxed{\sf v=u+at}$

$\\ \sf\hookrightarrow v=12.3+2\times 9$

$\\ \sf\hookrightarrow v=12.3+18$

$\\ \sf\hookrightarrow v=30.3m/s$