(11) Friction and Dynamics of Circular Motion

# (11) Friction and Dynamics of Circular Motion - Applying...

This preview shows pages 1–7. Sign up to view the full content.

Lecture 12 Applying Newton’s Laws

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

View Full Document
Goals of Today’s Lecture Goals of Today’s Lecture Being ableto apply Newton’s laws to any problemthat is not insane.
EXAMPLE: Incline and pulley, with friction m 2m 35 ° Same system, but μ S = 0.2 and μ k = 0.1 What happens when the system is released?

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

View Full Document
m 2m 35 ° N 2mg mg T T x y x Does the system moveat all? net 2 sin35 0.15 F mg mg mg = - = Net force, along the direction of motion, without friction: S,MAX S f N μ = Maximum static friction force: μ S = 0.2 μ k = 0.1 It does not move! Motion without friction S 2 cos35 mg μ = 0.33mg =
ACT: Magnitude of friction ACT: Magnitude of friction What is themagnitude of thestatic forcein thesystem wejust studied? A. 0.15 mg B. 0.33 mg C. 0.40 mg For thesystem to beat rest, f S should cancel out the resultant of the remaining forces (the net force without friction). Option C is beyond the maximum possible value. Option B would produce a net force to theleft along the incline! net , no f rict ion S,max 0.15 0.33 F mg f mg = = m 2m N 2mg mg T T f S 35 °

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

View Full Document
Example: Box on truck A box with mass m = 50 kg sits on theback of a truck. The
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern