| frame of reference = | Ground | Person | River | Boat | |
| Boat Speed | m/s | m/s | m/s | m/s |
Analysis:
The speed of the boat is not the same from each frame of reference. True or False?
From what frame(s) of reference is the boat stationary? __________________________
From what frame of reference(s) is the boat moving with negative velocity? ______________________________________________________________________________
From what frame of reference(s) is the boat moving with positive velocity? ______________________________________________________________________________
Observation #4 The Motion of Person in Two Dimensions
Refresh the webpage – Press the “Refresh” button at the top or the monitor screen.
Notice there are two number near the person (0.0 and 5.0). Those are vertical and horizontal velocity of that person at your frame of reference. The vertical velocity is 0.0 m/s and the horizontal velocity is 5.0 m/s. (Positive values indicated the direction is to the right and down on the monitor screen, negative values indicate the direction is up or left on the screen.)
While the animation is suspended :
Click near the left leg of that person and drag the mouse up and down, you are changing her (his) vertical speed. Set the vertical motion to +10 m/s and the horizontal speed to 0.0 m/s. Place the mouse cursor arrow on the ground and …
Click with right mouse button to resume the animation,
· That person will move toward the river, then, swim across the river and return to the ground. The motion is repeated as the animation runs.
· Record the vertical and horizontal velocity of the man on ground and in the water from each of these frames of reference.
| frame of reference = | Ground | River | Boat |
| Person’s Horizontal Velocity When on the GROUND | m/s | m/s | m/s |
| Person’s Vertical Velocity When on the GROUND | m/s | m/s | m/s |
| Person’s Horizontal Velocity When in the WATER | |||
| Person’s Vertical Velocity When in the WATER | m/s | m/s | m/s |
1. When does the person have only a vertical speed? ___________________________________
Why is the horizontal speed = 0.0 m/s? ____________________________________________
2.When does the person have a vertical and horizontal seed? ____________________________
3. When is his horizontal speed negative? ____________ Why is it negative? _______________