Forces

Use the force(s). 

Part 1: Forces Notes

Write the following notes in your journal.

Force = a push or a pull

Forces can be when things are in contact.

• Contact / Normal

  • [See Kahn Academy for more]

• Friction

  • [See our Friction lessons for more]

Or, forces can act at a distance.

• Gravity

  • [See our Gravity lessons for more]

• Magnetism

  • [See Kahn Academy for more]

Forces are interactions between two objects and can be balanced or not balanced.

Balanced forces = no change in motion

Unbalanced forces (net force) = change in motion

Newton's 3 Laws of Motion help us understand forces.

1. Inertia: objects resist a change in their motion

2. Force equals mass times acceleration

3. For every action there is an equal and opposite reaction

See printable scaffolded notes templates here. 

See a graded sample of the journal and notes here.

Part 2: Balanced and Unbalanced Forces Practice

Read Balanced and Unbalanced Forces and complete the assignment sheet.  

When finished with the assignment page, go into Google Classroom to review your T4 Science Practice - Data Analysis project. Take time to make revisions, resubmit your work, and request regrading. 

See this completed sample Balanced and Unbalanced Forces assignment sheet here to use for debriefing answers with class. 

Optional: Watch the bowling ball and feather episode.

Note: Some years we do this with laminated sheet protectors and whiteboard markers, some years we fill in a paper worksheet.

Part 3: Forces and Motion Simulation

Follow these instructions and answer the following questions in your journal as you do the simulation.

Net Force (Tug-o-War) Section:

Create a table like the one below but just including the 4 columns on the right and fill in the "Predicted Movement" column.

Then, as you do the tasks as described on the left in the Forces and Motion Basics simulation, fill in the "Actual Movement" and "Sum of Forces" columns. Note: you will need to check the boxes in the upper right to get the "Sum of Forces" values.

Friction (Refrigerator Moving) Section:

Play the Friction simulation for a bit, then answer these items in your journal.

1. In your own words, describe applied force.

2. In your own words, describe friction force.

3. In your own words, what is "net force"?

4. What is the relationship between net force and the rate at which an object changes its speed?

Debrief Questions - Answer these in your journal:

1. You and some friends are at the park . You find some rope and decide you’d like to play a game of tug-of-war. Unfortunately, there are 5 people so you can’t have an equal amount of people on each side. One of your friends suggests that the two biggest people should be on one side, while the three smaller people should be on the other side. Do you think this is a fair way to split up teams? Why or why not?

2. Question: What causes objects to move or stay still?

   1. Claim:

   2. Evidence:

   3. Analysis Questions/Reasoning:

      1. Give an example of a balanced force

      2. Give an example of an unbalanced force

      3. Do balanced or unbalanced forces cause a change in motion?

      4. How do you know this?

If you have time remaining, play the "Motion" simulation.  Check all the boxes in the upper right. 

Part 4: Forces Game

Goal: Move sediment (mass) all the way downstream without getting tagged by gravity.

1. Students start out in a 'river', standing at one end of a rectangular playing field, and they hold several (3-5) pieces of 'sediment' (could be pieces of paper, poker chips, etc.).

2. Each student represents the current or flow of water except for a few students who will be 'gravity' and run around in the field tagging people.

3. Have about 3/4 of the 'river' (the length of this rectangle) be a fast moving current, so the students are able to run.

4. Have a rope or other distinction a quarter of the way before the end of the field-- when they pass this rope, they enter the mouth of the river, where the current slows way down as fast moving water hits slow moving water. When they pass this rope, they have to walk.

5. The taggers (gravity) can still run, because gravity is a constant no matter if its slow or fast moving water.

6. Every time a student is tagged, they have to drop one of their pieces of sediment. If they make it to the end of the field, they drop all their chips. 

In this game, the rounds go really fast, with all the students running one time down the field. You could have a big collection of more 'sediment' and when they make it to the end, they circle back to the start and grab more chips and do it again.

Debrief Questions:

This game created a visualization of how sediment moves through a river and where more sediment settles in the river.

1. What force(s) help sediment move downstream?

2. Where is the most sediment deposition (in the fast or slow moving water)? Why is that?

3. Where was it easiest and hardest for gravity to do its job?

Forces Part 5: Bill Nye Motion

Watch Bill Nye Motion (season 5, episode 20). 

While you are watching, in your journal make two lists (make a t-chart):

1. List the things in the episode that you already learned in this unit.

2. List the new things you learned in this episode.

After the episode, debrief the lists as a class.

Forces Extension: New Physics

Learn and share some extremely cool physics projects with your class.

• Read the following article and watch the linked video.

• Create a short presentation on the information given and present it to the class by the end of the Physics unit.

• You may use powerpoint, google slides, or prezi to show visuals during your presentation.

• Your presentation should be between 5 and 10 minutes long.

• Large Hadron Collider Article

• NOVA sciencenow CERN

Follow these Assignment guidelines.