An object starts from rest at the origin and moves along the x axis with a constant acceleration of 4 m/s

2

. Its average velocity as it goes from x = 2 m to x = 8 m is:

6.9m/s

Explanation:

Given parameters:

Acceleration of the object  = 4m/s²

Distance = from x; 2m to x; 8m

Unknown:

Average velocity  = ?

Solution:

From the given parameters, we use the right motion equation to solve the problem.

   v² = u² + 2aS

v is the final velocity

u is the initial velocity

a is the acceleration

 S is the distance covered

 Distance  = 8m - 2m  = 6m

 Initial velocity  = 0m/s

The final velocity gives us the average velocity in this problem;

       v² = 0² + (2 x 4 x 6) = 48

      v = √48  = 6.9m/s

t = 1/400 h   ⇔ 0.0025 h ⇔ 9s ⇔ 0.15 m

any of the answers are correct.