# Thread: Measuring Circular Motion (Track Problem)

1. ## Measuring Circular Motion (Track Problem)

Samantha is jogging around the perimeter of a circular track at a rate of 10 ft/sec. The track has a radius of 100 yards. After 10 seconds, Samantha turns and runs along a radial line to the center of the circle. Once she reaches the center, she turns and runs along a radial line to her starting point on the perimeter. Assume Samantha does not slow down when she makes these two turns.

So what I am seeing of this problem is like this
1. She is jogging around the perimeter of a circle track at 10 ft/sec
2. Track has a radius of 100 yards
3. She runs along a radial line (I don't really know what radial line means, but does it mean it passes through the center of the circle?)
4. She reaches Center
5. She turns and runs along the radial line back to the starting point

Right?

So how far has Samantha traveled once she returns to his starting position?

I understand the perimenter part, but I am confuse on what it means when she runs along a radial line.
Can anyone help?
Thanks

2. ## Re: Measuring Circular Motion (Track Problem)

It means she runs along a radius - straight to the center of the circle from where she is after 10 seconds then straight from the center to her starting point.

3. ## Re: Measuring Circular Motion (Track Problem)

Oh ok, I see, thanks
So then the question: So how far has Samantha traveled once she returns to his starting position?
So what would be the steps then?

4. ## Re: Measuring Circular Motion (Track Problem)

How far does she go around the track (arc length - no circular motion equations needed here since you know how fast she's going and how long she goes)?
What is the radius (she covers this twice)?