If anyone know how to answer this problem and can give step by step instructions, I would really appreiate it. Thanks.
Before I start answering exact questions I want to work out what is happening. - I should have done it just by drawing the displacement graph. It is actually easier that way. I've done it both ways though. :)
The biker starts 1 mile north of Pidgeon lake. (the writing says so)
At first the biker is travelling north at 11mph.
after 1 hours he is 12km north of Pidgeon lake
At 1 hour he stops and changes direction and heads off south at 10mps
so he travels 2 hours south at 10mph that is 20miles south
he was 12miles noth to start with so now he is 8 south
At the end of the 3rd hour, he stops and changes direction again and heads north at 9mph
After the end of 4 hours (one hour later) he is exhausted and he stops.
In this last hour he has travelled 9miles north.
He was 8 miles south in the beginning so now he is 1 mile north.
So he is back to where he started at the beginning of the 4 hours.
It is actually EASIER to see this if you do the distance vs time graph FIRST.
I'll try and show you how.
It is much easier if you line the graphs up one under the other so that the times are in the same relative position.
You should be able to answer the questions now.