What is the average vector acceleration of a car that changes its velocity from 30km/h south to 40km/h east over a time of 5.0s?

Question

johnweldon1993 · Answer

Hmm, kinda worded weird

However..we know $\Large a = \frac{\Delta v}{t}$

Since the velocity is changing directions as well...it wont simplify COMPLETELY! but that's okay

$$\large a = \frac{40i - 30j }{5.0}$$

I hope you know that notation: "i" meaning in the x-direction and "j" meaning in the y-direction

So that acceleration vector would be

$$\large \vec{a} =  8i - 6j$$

johnweldon1993 · Answer

Which kinda makes sense if you think about it...the motion looks like

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johnweldon1993 · Answer

If we look on a coordinate plane

|dw:1443043692012:dw|

johnweldon1993 · Answer

So the resulting vector would be down down (so -j) and going right (so +i)

anonymous · Answer

shouldn't the j portion be negative and then you get 40--30

anonymous · Answer

And how would i give a numerical answer with an angle and km/h/s for velocity?