10_1425_web_Lec_08_Friction

# 10_1425_web_Lec_08_Friction - Friction Physics 1425 Lecture...

This preview shows pages 1–6. Sign up to view the full content.

Friction Physics 1425 Lecture 8 Michael Fowler, UVa.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Warm Up Question A brass cube and a flat brass disk of the same weight are on a flat board. The board is gradually tilted until sliding begins. Which slides first? A. The brass cube B. The flat brass disk C. Both at the same time
Free Body Diagram for Block on Slope At maximum pre-slide angle : Note frictional force is parallel to surface . Forces on block must add to zero as vectors since it is at rest. Notice: θ mg N mg N fr F fr F fr tan FN =

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Coefficient of Static Friction The magnitude of the maximum static frictional force (just before sliding) is found to be directly proportional to the normal force : is called the coefficient of static friction . If is the tilt angle where sliding begins, ( ) fr max S FN µ = S fr tan S µθ = fr θ
How Steep a Hill Can a Car Climb? Assuming a powerful engine, the incline is limited by the coefficient of static friction . The friction force from the road will push the car up the hill , provided: Bottom line:

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 8

10_1425_web_Lec_08_Friction - Friction Physics 1425 Lecture...

This preview shows document pages 1 - 6. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online