Computer Simulation: Forces, Friction and Motion
Introduction
Today we will learn about how the force put on an object determines how it will move when there is no friction and
when there is friction. Find the appropriate link on my resources page, OR:
1. Go to this address: http://phet.colorado.edu/en/simulation/forces--‐and--‐motion--‐basics and choose the sim under
PHYSICS, MOTION “Forces and Motion Basics”
2. Click the button that says “Run Now”. It might take a few minutes to load Find the sim in your downloads
folder & open it. If it says Java needs updated, click “Later”. The screen will look like this:
3. All answers will be recorded on this document.
Explore
1. Place a man on each side of the rope.
2. Hit the “go” button.
3. Hit the “Return” button. Try it again with either the same amount of men on each side or a different
amount of men on each side.
4. Hit the “Reset all” button. Click box next to “sum of forces” and “values,” continue putting men on each
side.
5. Hit the “Return” button.
Questions (Answer each question in the space provided)
1. How can you make the blue side win?
2. How can you make the red side win?
3. How can you get a tie on both sides?
4. If there was only one man pulling the cart what would the sum of forces consist of?
, Explain
Title: Forces, Friction, and Motion
Aim: How does applied force and friction affect the speed of an object?
The science concept is: If Sum of forces (or FNET) is not zero, object speeds up or slows down. If FNET is zero then its
speed is constant.
Part I-- Motion
1. Click the tab “Motion”
2. Check the boxes next to “ force, values, masses, and speed”
3. Click the pause button.
4. Place a box on the skateboard. Type 200 in the box. The screen should look like this:
5. Press the play button. Count to ten, what happens? (Look at the speedometer)
6. Repeat steps 4 and 5 with the refrigerator. (look at the speedometer)
7. Click the “Reset All” button.
8. Repeat steps 2--‐4 using different objects and different applied forces. You can also use the people.
9. What happens to the speed, does it slow down as different objects are added and the applied force is
different?
10. Why do you think this happens?
11. If forces are balanced, then the net force is zero. Is there a sum of forces, or net force here?
12. How much time does it take for 1 crate, 2 crates, a refrigerator, the man, the girl, and the mystery object,
with same applied force get to maximum speed? Maximum speed is reached when the hand on the
speedometer cannot go any further. (Record your answers in table below.) For the next part, you will need
a timer. You may use a handheld stopwatch/phone, OR, for an online timer, open a new
Introduction
Today we will learn about how the force put on an object determines how it will move when there is no friction and
when there is friction. Find the appropriate link on my resources page, OR:
1. Go to this address: http://phet.colorado.edu/en/simulation/forces--‐and--‐motion--‐basics and choose the sim under
PHYSICS, MOTION “Forces and Motion Basics”
2. Click the button that says “Run Now”. It might take a few minutes to load Find the sim in your downloads
folder & open it. If it says Java needs updated, click “Later”. The screen will look like this:
3. All answers will be recorded on this document.
Explore
1. Place a man on each side of the rope.
2. Hit the “go” button.
3. Hit the “Return” button. Try it again with either the same amount of men on each side or a different
amount of men on each side.
4. Hit the “Reset all” button. Click box next to “sum of forces” and “values,” continue putting men on each
side.
5. Hit the “Return” button.
Questions (Answer each question in the space provided)
1. How can you make the blue side win?
2. How can you make the red side win?
3. How can you get a tie on both sides?
4. If there was only one man pulling the cart what would the sum of forces consist of?
, Explain
Title: Forces, Friction, and Motion
Aim: How does applied force and friction affect the speed of an object?
The science concept is: If Sum of forces (or FNET) is not zero, object speeds up or slows down. If FNET is zero then its
speed is constant.
Part I-- Motion
1. Click the tab “Motion”
2. Check the boxes next to “ force, values, masses, and speed”
3. Click the pause button.
4. Place a box on the skateboard. Type 200 in the box. The screen should look like this:
5. Press the play button. Count to ten, what happens? (Look at the speedometer)
6. Repeat steps 4 and 5 with the refrigerator. (look at the speedometer)
7. Click the “Reset All” button.
8. Repeat steps 2--‐4 using different objects and different applied forces. You can also use the people.
9. What happens to the speed, does it slow down as different objects are added and the applied force is
different?
10. Why do you think this happens?
11. If forces are balanced, then the net force is zero. Is there a sum of forces, or net force here?
12. How much time does it take for 1 crate, 2 crates, a refrigerator, the man, the girl, and the mystery object,
with same applied force get to maximum speed? Maximum speed is reached when the hand on the
speedometer cannot go any further. (Record your answers in table below.) For the next part, you will need
a timer. You may use a handheld stopwatch/phone, OR, for an online timer, open a new
