Forces Web Quest
Physics Web Search: Forces Name_________________________
Period ________________________
Go to: http:
phet.colorado.edu/get_phet/simlauncher.php
Part 1: Forces in One Dimension
1. On the right, make sure friction is “off.”
2. Make sure the “File Cabinet” is selected.
3. Make sure initial position is -7.0 m
4. On the left, set the applied force to 400 N.
5. Graph each of the following options: Total (Net) Force, Acceleration, Velocity, and
Position.
! ! ! !
6. Predict how the four graphs will change (or not change) above if you select the
efrigerator, but leave the other settings the same.
a. Total Force: _______________________________________________________
. Acceleration: ______________________________________________________
c. Velocity: __________________________________________________________
d. Position: __________________________________________________________
7. Run the simulation again and redraw the four graphs from above. If your predictions
were inco
ect, comment below each graph as to why.
! ! ! !
8. Switch back to the filing cabinet, and turn friction “on.”
9. Run the simulation again with the Applied Force still set to 400 N.
10. What is the total force? _______ Why? ________________________________________
11. Using gravity as 9.8 m/s2, calculate the maximum force of static friction. The
coefficients of static friction are listed under “More Controls.” fs max= _______
12. Set the Applied Force equal to this value.
13. What is the Total Force? __________
14. Add 1 N to the applied force you just used and run the simulation.
http:
phet.colorado.edu/get_phet/simlauncher.php
15. What is the Total Force? __________ Why is it not 1 N? _________________________
________________________________________________________________________
16. Click the “Textbook.” Calculate the maximum force of static friction (continue to use 9.8
m/s2 for gravity), add 1 N to this number, and set the Applied Force equal to this value.
Applied Force = ___________
17. Run the simulation.
18. What is the frictional force listed on the graph: _______
19. Use this frictional force to calculate the coefficient of kinetic friction: ____________
20. If you look under more controls it says the coefficient of kinetic friction is .2. This is not
technically wrong, any idea why? ____________________________________________
(Wikipedia “Rounding” – go to: Round Half to Even). You can try changing the value
to .25 and see what happens, and also .35.
21. Given that the textbook started -7.0 m from the origin, calculate the exact time that the
textbook will get to the origin. Show your work, and check the position graph to see if
you are close. t = _______.
Part 2: The Ramp
1. Note that gravity in this lab is 9.8 m/s2
2. Click on the filing cabinet
3. Set the ramp angle equal to 20° (make sure to hit enter so it changes)
4. Click “Go” at the bottom right, and then click “Pause” before the filing cabinet slides off
the ramp.
5. Show work to explain where the values XXXXXXXXXXN, and XXXXXXXXXXN come from.
6. Set the Applied Force equal to 50 N.
7. Calculate the net force acting on the filing cabinet. Show your work.
8. Run the simulation, and calculate the time it will take the filing cabinet to reach the end
of the ramp (remember it moves 10 m). Check the top left corner of the screen and note
the time it takes to reach the end of the ramp t = _________. Show your work.