While john is traveling along a straight interstate highway, he notices that the mile marker reads 252km. He travels until he reaches the 149km marker and then retraces his path to the 168km marker. What is his dispacement? How far has he traveled?

What do you understand to be the difference between distance and displacement?

I know what distance and displacement are, and I'm 99.9% sure I got this question right, but for my physics class we have to submit our answers online and it keeps marking me wrong for this one. I just want to see someone else's answer so that I know it's not just me making a mistake.

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Originally Posted by lillib123

I know what distance and displacement are, and I'm 99.9% sure I got this question right, but for my physics class we have to submit our answers online and it keeps marking me wrong for this one. I just want to see someone else's answer so that I know it's not just me making a mistake.

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So what answers did you give that the online system saifd was wrong?

Hint: it could be that with this problem the convention is that if you travel in a direction of decreasing mile markers that your displacement is becoming more negative.

Ahh, thanks, the negaive displacement was the problem. I got it now. :)