Frames of Reference
Webquest
Objectives: Students will gain a better understanding of the following
- The concept of "frames of reference"
- A simple mathematical relationship between the motion of objects as viewed from different frames of reference
Directions: Carefully read each of the numbered questions below, then check out the "Riverboats" link. Follow the directions in the questions and then answer them. More importantly, understand the answers to each question. (Let me know if there are any problems.)
Frames of Reference
- Riverboats - Various frames of reference are examined.
Answer the following questions while examining the "riverboats" link. Make sure you click the "info" box to show the relative velocities.
- Draw a diagram of the animation. (You can right click on it to freeze it.)
- Make sure the mouse is on the grey portion of the animation (land). Record on your diagram the "relative" velocities of the man (blue) walking, the red boats, and the speed of the river. Include the direction of the velocities as well!
- Now make sure the mouse is in the lovely green river. The note that the velocities of each change. On a separate diagram, record the velocities of the man walking, the red boats and the apparent speed of the land.
- Why does the speed of the river disappear when the mouse is on the river, and the land speed disappear when you move the mouse back to the land?
- Explain why the apparent speed of the red boats change when observing the speed from the land verses the water. What is the mathematical relationship?
- Explain why the apparent speed of the man changes when observing his speed from the land verses the water. What is the mathematical relationship?
- How are the speeds of the land and water related to one another when viewed from the opposite positions (frames of reference)?
- Now place the mouse on one of the red boats. On yet a third diagram, record the speeds of the river, the man and the land.
- Compare the speed of the man walking relative to the land (mouse on grey) to the speed of the man walking relative to the red boat (mouse on red boat). Explain the observation (using the speed of the red boat).
- Compare the speed of the river relative to the land (mouse on grey) to the speed of the river relative to the red boat (mouse on red boat). Explain the observation (using the speed of the red boat).
- Explain in your own words, the concept of frames of reference.