Name_________________________________________ Date_____________

Force on an Elevator

Site 1:  http://www.eduplace.com/kids/hmsc/  --click on 6, click on Unit F:  Energy, Forces, and Motion, click on Discover Simulations
The elevator will travel from floor 1 to floor 100 at various speeds.   You will take data on the elevator as it moves to fill out this chart.  You will probably need to play and reset the elevator many times as you take data.

Analysis:

1.  When the elevator speeds up, what happens to the girl’s weight? _________________________________
When the elevator slows down, what happens to the gir’ls weight? ________________________________

2.   The girl’s weight starts at 588 N, it shifts during the rise of the elevator and then returns to 588N for most of the trip. 
Why is her weight 588N even though the elevator is pushing her up and still moving?

3.  When the accelerometer is reading a negative number, what is the elevator doing? 

4.  When the speedometer is reading a negative number, what is the elevator doing?

5.   When will the girl have a zero weight (free fall)?  Think about the acceleration of gravity and the acceleration of the elevator.

Projectile Motion:  

Site 2: http://phet.colorado.edu/simulations/   -- click on projectile motion link -- click on “run now”

Simulation tips: 

The square yellow box can be used to measure distance.
If you need to rest simulation to its original starting points, enter these value: Angles = 80; Initial speed = 18; mass =2, diameter =.1.

You can see the range, height and time in the top boxes.

Maximize the screen

Instructions:  Answer these questions by changing the variables.   Remember it is best to change only one variable (the one you are testing) and leave the others constant.

Question 1:   If you cut the projectile’s velocity in half, will the range also be cut in half.  Show your data below.

Question 2:  Do objects with different weights travel farther, faster or higher?   How does air resistance affect these distances?    Fire each of the items first with no air resistance, then click the air resistance button.  Keep the angle at 80 and the speed at 18 for this simulation

Question 3:  What angle, speed and mass can be used to hit the target? 
There are several answers here; you just need to find three that work.