- #1

undefinable

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## Homework Statement

Alvin races Ophelia to Physics class. Alvin has a headstar of 13m and travels at a constant speed of 7m/s. Phelia is initially traveling at 1.2m/s but then begins to accelerate at 1.5m/s2 until she reaches the physics classroom 100m away from her.

Who wins the race? when and where did ophelia catch up? (both metres and time)

## Homework Equations

d=vit+1/2(a)(t)2+di

## The Attempt at a Solution

Who wins the race? I was able to figure out that alvin completed the race at 12.4s and phelia competed the race at 10.8s (though I'm not sure if its right)

I got stuck trying to find out WHEN they caught up. I tried setting the equation to

vit+1/2(a)(t)2+di=vit+1/2(a)(t)2+di

and plucking in the numbers for both sides but when I tried to find the variable for time, I put it into the quadratics formula. I ended up have no real roots (square rooting negatives)