Question

A drag racer accelerates uniformly over a course 400m long. Determine the car's acceleration if it reaches a top speed of 120 m/s. Assume that the car starts from rest.

Answer 1

• Initial velocity=u=0m/s
• Final velocity=v=120m/s
• Distance between course=s=400m
• Acceleration be a

According to thrid equation of kinematicsthird equation of kinematics

$\\ \rm\hookrightarrow v^2-u^2=2as$

Isolate the equation for a

$\\ \rm\hookrightarrow a=\dfrac{v^2-u^2}{2s}$

$\\ \rm\hookrightarrow a=\dfrac{120^2-0^2}{2(400)}$

$\\ \rm\hookrightarrow a=120^2/800$

$\\ \rm\hookrightarrow a=16m/s^2$