1. AIM : How do we solve Friction, Forces and Gravity problems? DAY 4: Forces & Gravity Activity Sheets OBJ: Given activity sheet and video SWBAT solve friction, forces and gravity problems with 70% accuracy. DN: Take out Friction 3 and Friction Activity Sheets ACT: Review Results: Friction 3 and Friction Activity Sheets. Complete Forces (Q: 2, 4, 9, 10 only) and Gravity Activity Sheets HW: Complete 3 types of Motion and What makes things fall Activity Sheets; Study for SFFG Exam; SFFG Exam, Thursday April 30; NLSM Exam, May 28?

2. Friction 3 Activity Sheet-A.K. 1. 16N 2. Because it makes it easier to move the object; Certain objects can be very heavy and because static friction is more than sliding, rolling and fluid friction. 3. When metal parts are rubbing (scraping) against each other (ex: watch, engine) 4. more 5. less; reduced 6. lubricant 7. reducing

3. Friction 3 Activity Sheet-A.K. 1. decreases 2. less 3. more (more roughness) 4. less (more smoothness) 5. is 6. increasing 7. increase 8. greater b

4. Friction Activity Sheet-A.K. 1. 4 2. 4 3. 4 4. 4 5. 40 joules 6. least amount of friction; energy input is closest to energy output which shows an increase in efficiency. 7. spring scale 8. glue/attaching sandpaper to table; make table surface rough; adding additional mass/weight to block 9. reduces friction by rolling friction

5. Forces Activity Sheet-Answer Key 1. 3 2. 1 3. 2 4. 2 5. 2 6. 3 7. 2 8. 2 9. 3 10. 2

6. Gravity Activity Sheet-A.K. 1. 1 2. 4 3a. A 3b. The closer the distance, the more the gravity 3c. 4. B will move; B may hit another satellite; B may crash to earth; B may fly out into space

7. Gravity Activity Sheet-A.K. 4.More mass (larger size) ~ stronger the gravitational pull; less mass (small size) ~ weaker the gravitational pull. 5. Mercury, Mars, Pluto 6. Pull the bow string farther (more) 7. Gravity pulls arrow down so that the trajectory (path) is curve/arc–shaped.