1. Day 36, Thursday, 15 October, 2015 Tension and Inclined Planes Review 4 Fundamental Forces Hanging Weight Tension Problems Inclined Planes Beware the mysterious sin/cos shift

2. Some Common Forces 1. Friction 2. Normal 3. Restoring force of a spring 4. Tension 5. Thrust 6. Gravity (weight)

3. Characteristics of the 4 Fundamental Forces

4. Inclined Plane Problems: Resolve the force of gravity into parallel and perpendicular components

5. Diagram

6. Work Problems for Class 1. A skier goes down a hill 2. A hanging sign supported from 2 sides 3. A sign hung in an alleyway

7. Skier going down a hill A 62 kg skier goes down a hill with a 37° slope. The coefficient of friction between the snow and the skis is 0.15. How fast is the skier going 5 seconds after starting from rest? 37°

8. Tension Tension in hanging weight support wires Hanging sign problem Physics by Glencoe (2002), p. 151 Joe’s sign problem Physics by Glencoe (2002), p 171 # 34

9. Hanging sign supported from 2 sides A sign that weighs 168 newtons is supported by 2 wires that form a 22.5° angle from the horizontal. Find the tension in the wires. 168 22.5° AB

10. Sign in an alley A sign weighing 750 newtons is supported by wire A on the left side of an alley that makes an angle of 30° with the vertical and another wire that stretches horizontally across the alleyway. What is the tension in wire B? 750 30° A B

11. Credits 4 forces chart www.howgravityworks.com Resolve the Force of Gravity Sparknotes.com Free Body Diagram www.cdli.ca

12. Credits II Hanging sign problem Physics by Glencoe, 2002, P. 151 Sign in an alley problem Physics by Glencoe, 2002, p. 171, # 34 Skiing Downhill Physics by Glencoe, 2002, p. 153