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The Science of Skates, Friction Friend and Foe

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  Document Type: Lesson Plan
  Lesson Plan Type: Video,Interactive Instruction
  Subject: Science
  Grade Level: 6,7,8,9
  Time: 50 minutes
  Last Updated: 02-11-2010
     
  Keywords:
     
     
 
Created/Provided by:
NBC Learn
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CALIFORNIA STATE STANDARDS ADDRESSED

Science/8/Focus on Physical Science
1.0 The velocity of an object is the rate of change of its position. As a basis for understanding this concept: a. Students know position is defined in relation to some choice of a standard reference point and a set of reference directions. b. Students know that average speed is the total distance traveled divided by the total time elapsed and that the speed of an object along the path traveled can vary. c. Students know how to solve problems involving distance, time, and average speed. d. Students know the velocity of an object must be described by specifying both the direction and the speed of the object. e. Students know changes in velocity may be due to changes in speed, direction, or both. f. Students know how to interpret graphs of position versus time and graphs of speed versus time for motion in a single direction.
2.0 Unbalanced forces cause changes in velocity. As a basis for understanding this concept: a. Students know a force has both direction and magnitude. b. Students know when an object is subject to two or more forces at once, the result is the cumulative effect of all the forces. c. Students know when the forces on an object are balanced, the motion of the object does not change. d. Students know how to identify separately the two or more forces that are acting on a single static object, including gravity, elastic forces due to tension or compression in matter, and friction. e. Students know that when the forces on an object are unbalanced, the object will change its velocity (that is, it will speed up, slow down, or change direction). f. Students know the greater the mass of an object, the more force is needed to achieve the same rate of change in motion. g. Students know the role of gravity in forming and maintaining the shapes of planets, stars, and the solar system.
 
BRIEF DESCRIPTION
Through discussion, demonstrations, and a writing assignment, students will investigate the helpful and hindering roles of friction in various sports and present their findings to the class.

 

 
PROCEDURES
 
Goal(s):
Students will review their knowledge of friction. They will analyze the helpful and hindering roles of friction in different sports. Students will also develop their communication skills by presenting their ideas to their peers.
 
Specific Objectives:
Students will be able to:
  1. Express a conceptual definition of friction.
  2. Explain that amount of friction depends in part upon the types of surfaces involved.
  3. Explain that the amount of friction depends in part upon the force between 2 surfaces.
  4. Explain conceptually the difference between kinetic (sliding) friction and static friction.
  5. Identify at least 3 sports examples where friction is helpful to the athlete.
  6. Identify at least 3 sports examples where friction is a hindrance to the athlete.
 
Required Materials:
Pencil and Paper are the only required materials.

Suggested materials include:

1 Whiteboard and Markers per group of 3 students, any existing equipment to qualitatively demonstrate friction (spring scale and block, ramp, surfaces with different coefficients of friction., force probe and graphing software, hover puck or dry ice to show an objects motion under conditions of low friction, etc.)
 
Anticipatory Set (Lead-in):
Ask the students what is meant by the phrase “there seems to be an atmosphere of friction between the frustrated lab groups.” Discuss that, as has probably already been discussed, many engineers spend their careers trying to reduce friction, inside of engines or generators, in mechanical equipment, etc., although this lesson could just concentrate on friction between 2 surfaces, you may also want to include and discuss air “friction” (air drag, air resistance).

Ask students to share instances where friction is helpful (stopping, speeding up or steering a car, playing basketball, walking, not letting things slide off tables, etc.)

Tell them that by the end of the lesson, they are going to analyze the roles of friction in a sport or activity of their choice in order to determine in what aspects it is a friend, foe, or both.
 
Lesson Plan Procedure:
This lesson assumes prior knowledge of friction, but it is still recommended to review the basics.

  1. One simple (equipment-less) way to review the basics of friction is to have the students rub their hands together and discuss:  (I.) What happens to the force of friction when you push your hands together while rubbing? (Discuss that friction is proportional to the normal force between the surfaces.) (II.) Ask the students to hypothesize the friction if they put lotion or oil on their hands? Tar? Adhesive? (Discuss that friction is also proportional to the coefficient of friction.) (III.) If they push their palms together hard enough, they may find that they can’t slide anymore, and you can use this to review static friction.
  2. Show them the NBC Learn Video: The Science of Skates. Ask them to note the clever engineering tricks used to minimize friction, but also encourage them to look for examples of desired friction.
  3. After the video, make a class list of some of the areas and strategies where skaters try to eliminate friction. Then discuss situations where friction is a good thing in sports or other activities. For each example, encourage the students to identify whether it is static or kinetic friction and how the strategies to maximize or minimize friction relate to the coefficient of friction and the normal force.
  4. After the video, have them work in small groups to brainstorm a different sport or activity and analyze the role of friction. You can give them the attached worksheet (Group Activity Worksheet Friction: Friend, Foe, or Both) or simply show it to them and have them organize their whiteboards in a similar format.
  5. After about 15 minutes you may want to have one or two groups present their boards and help facilitate the discussion to make sure they have addressed the concepts of static friction versus kinetic friction, normal force, and coefficient of friction.
  6. Having clarified the physics analysis on the first board or two, give the remaining group a few minutes to make any modifications they want to on their boards.
  7. Present the other boards via some other strategy:
  • Groups pair up and take turns presenting to one another.
  • Or, a gallery walk where groups rotate around, have a few minutes to read, and use sticky notes to make at least one comment on each board.
  • Or, send one representative from each group around to share with other groups.
 
Assessments & notes
 
Plan for Independent Practice:
For homework, students can complete the worksheet for a new sport or activity not discussed in class.
 
Assessment Based on Objectives:
The above homework assignment can also be used as an assessment.
 
Possible Connections to Other Subjects:
Math: Students can use a spring scale to measure the friction of a block of a known mass. They can put masses on top of the block and measure the new frictional force. They can graph force of friction versus the total mass and analyze the results.
 
Adaptations & Extensions:
Students can use a spring scale to measure the friction of a block of a known mass. They can put masses on top of the block and measure the new frictional force. They can graph force of friction versus the total mass and analyze the results.
 
Additional Notes:
This lesson assumes prior knowledge of the concepts of kinetic friction, static friction, coefficient of friction, and normal force.
 
 
 
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Submitted by NBCLearn on Tue, 01/26/2010 - 04:19


Title:

The Science of Skates, Friction Friend and Foe

Grade Level:

6,7,8,9

Subject:

Science

Author:

nbclearn

Time:

50 minutes

Lesson Plan Type:

Video,Interactive Instruction

Keywords:

Ice Skates, Friction, Coefficient of Friction, Acceleration, Newton’s 2nd Law, Air Resistance, Drag, Normal Force, Kinetic (Sliding) Friction, Static Friction, olympics

Brief Description:

Through discussion, demonstrations, and a writing assignment, students will investigate the helpful and hindering roles of friction in various sports and present their findings to the class.

 


California State Standards Addressed:

Science/8/Focus on Physical Science)1.0,2.0

Related Links:

Link 1:

Goal(s):

Students will review their knowledge of friction. They will analyze the helpful and hindering roles of friction in different sports. Students will also develop their communication skills by presenting their ideas to their peers.

Specific Objectives:

Students will be able to:
  1. Express a conceptual definition of friction.
  2. Explain that amount of friction depends in part upon the types of surfaces involved.
  3. Explain that the amount of friction depends in part upon the force between 2 surfaces.
  4. Explain conceptually the difference between kinetic (sliding) friction and static friction.
  5. Identify at least 3 sports examples where friction is helpful to the athlete.
  6. Identify at least 3 sports examples where friction is a hindrance to the athlete.

Required Materials:

Pencil and Paper are the only required materials.

Suggested materials include:

1 Whiteboard and Markers per group of 3 students, any existing equipment to qualitatively demonstrate friction (spring scale and block, ramp, surfaces with different coefficients of friction., force probe and graphing software, hover puck or dry ice to show an objects motion under conditions of low friction, etc.)


Anticipatory Set (Lead-in):

Ask the students what is meant by the phrase “there seems to be an atmosphere of friction between the frustrated lab groups.” Discuss that, as has probably already been discussed, many engineers spend their careers trying to reduce friction, inside of engines or generators, in mechanical equipment, etc., although this lesson could just concentrate on friction between 2 surfaces, you may also want to include and discuss air “friction” (air drag, air resistance).

Ask students to share instances where friction is helpful (stopping, speeding up or steering a car, playing basketball, walking, not letting things slide off tables, etc.)

Tell them that by the end of the lesson, they are going to analyze the roles of friction in a sport or activity of their choice in order to determine in what aspects it is a friend, foe, or both.


Lesson Plan Procedure:

This lesson assumes prior knowledge of friction, but it is still recommended to review the basics.

  1. One simple (equipment-less) way to review the basics of friction is to have the students rub their hands together and discuss:  (I.) What happens to the force of friction when you push your hands together while rubbing? (Discuss that friction is proportional to the normal force between the surfaces.) (II.) Ask the students to hypothesize the friction if they put lotion or oil on their hands? Tar? Adhesive? (Discuss that friction is also proportional to the coefficient of friction.) (III.) If they push their palms together hard enough, they may find that they can’t slide anymore, and you can use this to review static friction.
  2. Show them the NBC Learn Video: The Science of Skates. Ask them to note the clever engineering tricks used to minimize friction, but also encourage them to look for examples of desired friction.
  3. After the video, make a class list of some of the areas and strategies where skaters try to eliminate friction. Then discuss situations where friction is a good thing in sports or other activities. For each example, encourage the students to identify whether it is static or kinetic friction and how the strategies to maximize or minimize friction relate to the coefficient of friction and the normal force.
  4. After the video, have them work in small groups to brainstorm a different sport or activity and analyze the role of friction. You can give them the attached worksheet (Group Activity Worksheet Friction: Friend, Foe, or Both) or simply show it to them and have them organize their whiteboards in a similar format.
  5. After about 15 minutes you may want to have one or two groups present their boards and help facilitate the discussion to make sure they have addressed the concepts of static friction versus kinetic friction, normal force, and coefficient of friction.
  6. Having clarified the physics analysis on the first board or two, give the remaining group a few minutes to make any modifications they want to on their boards.
  7. Present the other boards via some other strategy:
  • Groups pair up and take turns presenting to one another.
  • Or, a gallery walk where groups rotate around, have a few minutes to read, and use sticky notes to make at least one comment on each board.
  • Or, send one representative from each group around to share with other groups.

Closure (Reflect Anticipatory Set):



Plan for Independent Practice:

For homework, students can complete the worksheet for a new sport or activity not discussed in class.

Assessment Based on Objectives:

The above homework assignment can also be used as an assessment.

Possible Connections to Other Subjects:

Math: Students can use a spring scale to measure the friction of a block of a known mass. They can put masses on top of the block and measure the new frictional force. They can graph force of friction versus the total mass and analyze the results.

Adaptations and Extensions:

Students can use a spring scale to measure the friction of a block of a known mass. They can put masses on top of the block and measure the new frictional force. They can graph force of friction versus the total mass and analyze the results.

Additional Notes:

This lesson assumes prior knowledge of the concepts of kinetic friction, static friction, coefficient of friction, and normal force.


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