Question

The motion of an object undergoing constant acceleration can be modeled by the kinematic equations. One such equation is xf=xi+vit+12at2xf=xi+vit+12at2 where xfxf is the final position, xixi is the initial position, vivi is the initial velocity, aa is the acceleration, and tt is the time. Let's say a car starts with an initial speed of 15 m/sm/s, and moves between the 1000 mm and 5000 mm marks on a roadway in a time of 60 ss. What is its acceleration?

Answer 1

Answer:

a = -04978 m / s²

Explanation:

For this exercise we can use the kinematics equations, as the initial speed, distance and time indicate, we can use

        x = x₀ + v₀ t + 1 /2 a  t²

       ½ a t² = x-x₀ - v₀ t

       a = (x-x₀ - v₀ t) 2 / t²

let's reduce the magnitudes to the SI system

     x₀ = 1000 mm = 1 m

     x  = 5000mm = 5m

let's calculate

     a = (5 - 1 - 15 60) 2/60²

     a = -04978 m / s²

negative sign indicates that braking is related