contestada

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.

Respuesta :

  • Initial velocity=u=0m/s(As it starts from rest)
  • Final velocity=v=120m/s
  • Distance between course=s=400m
  • Acceleration be a

Apply third equation of kinematics

[tex]\\ \rm\hookrightarrow v^2-u^2=2as[/tex]

Isolate the equation for a

[tex]\\ \rm\hookrightarrow a=\dfrac{v^2-u^2}{2s}[/tex]

[tex]\\ \rm\hookrightarrow a=\dfrac{v^2}{2s}[/tex]

[tex]\\ \rm\hookrightarrow a=120^2/800[/tex]

[tex]\\ \rm\hookrightarrow a=18m/s^2[/tex]