Motion Detectors, Cyclists, and Motion Maps

Hey everyone!  Don't worry, I'm still here, but this week, I've come to the realization that my blogs are long... VERY long.  I've realized that you guys probably don't want to read all that lengthy garble, so I'm going to try to cut it down, just for you.  You had better feel special...

Anyway, this week in class, we discussed motion... again.

I have this odd feeling that the motion section is going to last for a long while, seeing as how confused the class is, as well as myself at certain points in time.

For most of the week, we had a class discussion on this worksheet we did called "Unit 2 Worksheet 1".  I know guys, I love the name just as much as you do.

Question 1 

Anyway, for this worksheet, we were asked multiple questions about this graph for question 1:

If you didn't read the little blip above the graph, this graph is specifically a position vs. time graph and it has to do with 2 cyclists, Cyclist A and Cyclist B.  Position is the y-axis (in meters) and time is the x-axis (in seconds).  In our class discussion, we found:

• The cyclists do not start at the same point.  Cyclist B starts before cyclist A because it is farther up the y-axis.
• The reference point is the origin which is where Cyclist A started.
• When the time is 7 seconds, Cyclist A is ahead because it is above Cyclist B, so it is in a position which is farther away.
• When the time is 3 seconds, cyclist A is travelling faster because its slope is steeper.  Although, this is what I believe.  There is some controversy in my class on whether or not the slope is the speed.
• Their velocities aren't equal at any time.  Again, this is what I believe because it is still being debated.  To me, their slopes are never the same, so their velocities aren't.
• At the intersection of the two lines, they are at the same position at the same time.  However, they are not at the same speed or velocity.
• The biker's speeds are constant because it is a straight line.  My belief again.
• My theory: Velocity=Distance/Time and since position is measured in distance (y-axis) and time is the x-axis, it only makes sense that the slope is velocity.
• You don't travel a position, you travel a distance, so a certain point is a position, while the line is made up of tons of different positions.
• Position= Speed times Time + Starting Position or P=Speed times t + Po

Question 2

For question 2, we used the original graph and another:

We were asked basically the same questions as in question 1.  As a class, we found:

• Compared to the old Cyclist A, the new Cyclist A is going in the opposite direction.  It is going towards the x-axis or the starting point, instead of heading away from it.
• Compared to the old Cyclist B, the new Cyclist B is going the exact same speed.
• Cyclist A has the greater speed due to steeper slope.  Again, very controversial.
• At the intersection, they are at the same position at the same time.
• During the first 5 seconds, neither cyclist traveled farther.  At exactly 5 seconds, both cyclists end up at the same position.  The speed at which they got there doesn't make a difference.  They still ended up in the same place.

New Lab

We also started a new lab with motion sensors and motion maps.  However, since we haven't finished it yet, I will save it for  my next blog.  Also, does anyone know what a motion map is?

Reflection

This week, I have decided that my new goal is to speak only when I am absolutely necessary, and when I have a question of course.  If there is ever a lag in the conversation, I will try to come up with something to say or ask to keep the conversation going, as well as to benefit others.  Also, as mentioned before, my blogs are very long and "thorough" as my teacher would say.  I did try to cut it down, but I'm not sure it worked.  I just have so much to say.