At a certain time a particle had a speed of 11 m/s in the positive x direction, and 1.3 s later its speed was 78 m/s in the opposite direction. What was the average acceleration of the particle during this 1.3 s interval?(adsbygoogle = window.adsbygoogle || []).push({});

2. Relevant equations

I have Vi=11m/s, Vf=78m/s and t=1.3 m/s

3. The attempt at a solution

My attempt at the solution has been the formula of (78-11)/1.3. This has gotten me the answer of 51.54 and I at am a real loss. I have read my book over and over and I juts need some guidance.

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# Homework Help: Average acceleration problem having trouble

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