Forces and the Laws of MotionSection 4 Friction Click below to watch the Visual Concept. Visual Concept
{"Image DocumentName": "Friction Click below to watch the Visual Concept. Visual Concept", "Image ImageDescription": "This Visual Concept discusses the nature of friction and the factors that affect the amount of friction. Before running the video, ask students to explain what causes the force of friction. Lead this discussion by asking students how the force of friction is affected by changing the types of surfaces or by adding a lubricant (such as water or glycerin on glass tubing). They should see these things clearly when you play the video. Make sure the students are focused on the magnified view of the surfaces. This will help them understand the effect of increased normal force and the effect of different surface types. During the comments on swimming, ask them how swimmers reduce the force of friction. Have them draw a free-body diagram of a swimmer showing the force propelling him forward (water pushing against his hand) and the frictional force in the opposite direction. Ask students how the swimmer can accelerate. They should respond that he can reduce friction or increase the force of the water on his hand.", "Image XResolution": "37", "Image YResolution": "37", "Image ResolutionUnit": "Pixels/Centimeter", "Image Software": "SlidePlayer", "Image YCbCrPositioning": "Centered"}