Upcoming SlideShare
×

# 4 4 notes

270 views

Published on

Published in: Technology, Education
0 Likes
Statistics
Notes
• Full Name
Comment goes here.

Are you sure you want to Yes No
• Be the first to comment

• Be the first to like this

Views
Total views
270
On SlideShare
0
From Embeds
0
Number of Embeds
18
Actions
Shares
0
2
0
Likes
0
Embeds 0
No embeds

No notes for slide

### 4 4 notes

1. 1. 4-4 Review
2. 2. Normal Force• Equal in magnitude to Fg, but opposite in direction• Perpendicular to the surface• Fn = mg(cos of angle) –Angle is between normal force and a vertical line, and also contact surface horizontal line –See Figure 4-20 (b)
3. 3. Static Friction• Static friction (Fs) – resistance force that keeps an object from moving – Small push on a heavy object doesn’t cause it to move – Equal to the applied force as long as the object doesn’t move (Fs = -Fapplied) – Fs,max – applied force is a great as it can be without causing the object to move
4. 4. Friction (cont.)• Kinetic friction (Fk) – force that opposes an object’s motion – Always less than Fs,max – Net external force acting on an object is equal to difference between applied force and force of kinetic friction (F - Fk) – Depends on surfaces in contact
5. 5. Friction (cont.)• Coefficient of friction – expresses the dependence of frictional forces on particular surfaces in contact• Represented by lower case greek letter,• See formulas and table 4.2 on page 144