Calc. the car's average acceleration

[hullio]

Help please :)

Homework Statement

A Car with a velocity of 25m/s[E] changes its velocity to 25m/s in 15s. Calc. the car's average acceleration.

Homework Equations

Aav= Vf - Vi / T

The Attempt at a Solution

I know that the angle is = to 45 degrees S of W since it's a right angle triangle and two sides are equal, therefore, 90 + 45 + 45 = 180.

 

[radou]

You are dealing with vectors here? Do you know how to express the formula you gave with vectors?

 

[hullio]

Yes dealing with vectors. Express the formula with vectors? I don't think so...? I've been learning all this Dx and Dy stuff in class. X-components, y-compenents, sin/cos/tan stuff.

 

[Lemm]

Well X and Y components are the axis, or directions North is +Y, South is -Y, East is +X, West -X.

Just start by making a quick outline of the problem, on a set of axis, that always helps.

 

[learningphysics]

Are you familiar with this type of notation: $$\vec{r} = 34\vec{i} + 25\vec{j}$$ (just an arbitrary vector... nothing to do with the problem... i denotes a unit vector in the x-direction... j denotes a unit vector in the y direction)