## Due 3:30 pm, Thursday, September 10th

Physics 105, Fall Term, 2009

Did you complete the reading assignment?

Yes
No

## KEY CONCEPTS:

1) The motion of an object can be broken down into separate x and y components.

2) Time links motion in the x and y directions together.

Most motion we observe in life does not just happen in a single direction. Most motion we observe needs at least two dimensions to describe it.

Go to: http://www.walter-fendt.de/ph14e/projectile.htm and familiarize yourself with the controls. You will only want to change the initial height, initial speed, and angle of inclination when working with this applet. You will also need to use the 'Start' and 'Reset' buttons to watch the projectile move and clear it so that you can change the controls and watch a different trajectory. Finally, you can change what type of information you are observing with the bubbles on the bottom-right side of the applet. The position setting will tell you the horizontal and vertical positions and maximum distances as well as the time; the velocity setting will tell you the velocity components, the total velocity, and the angle of inclination of the objects motion; the acceleration setting will tell you the objects acceleration. You can also click the 'Slow Motion' check box to be able to see what is happening as the projectile moves.

Select the position setting and launch projectiles with different initial heights, initial speeds, angles of inclination, and masses. Increasing which setting(s) will always increase the maximum height reached by the projectile? (select all that apply)

Initial height
Initial speed
Angle of inclination
Mass
None

Increasing which setting(s) will always decrease maximum height reached by the projectile? (select all that apply)

Initial height
Initial speed
Angle of inclination
Mass
None

Increasing which setting(s) will always increase the maximum distance reached by the projectile? (select all that apply)

Initial height
Initial speed
Angle of inclination
Mass
None

Increasing which setting(s) will always decrease maximum distance reached by the projectile? (select all that apply)

Initial height
Initial speed
Angle of inclination
Mass
None

Increasing which setting(s) will always increase the amount of time the projectile is in the air? (select all that apply)

Initial height
Initial speed
Angle of inclination
Mass
None

Increasing which setting(s) will always decrease the amount of time the projectile is in the air? (select all that apply)

Initial height
Initial speed
Angle of inclination
Mass
None

Now select the velocity setting and launch projectiles with different initial heights, initial speeds, angles of inclination, and masses. Which value stays consistent throughout the flight of the projectile? (select all that apply)

Velocity in the x direction
Velocity in the y direction
Total velocity
Angle of inclination
None

What does the answer above mean?

Select the acceleration setting and launch a projectile. What is causing the acceleration?

FEEDBACK

The comments entered in these last two boxes go into a big anonymous data file that I will use to guide the lectures of the day. That means two things:

1) If you have a specific question or concern and would like an individual answer you will need to come by the office or send an email.
2) If you really want to get an anonymous comment to me before the lecture, it must be submitted before 11am that day.

Was there anything that you didn't understand in the reading assignment?  What was confusing to you?