advertisement

Homework: Torque and Simple Machines 1. Look at Figure 14: Is the energy gained by the pins greater than, equal to or less than the energy lost by the bowling ball? Read pg 254 and 255 and answer the following: 2. 3. 4. 5. What is center of mass? What is axis of rotation? What is Torque? The farther the force is from the axis of rotation, the ________________________it is to rotate and the more ________________ is produced. 6. The perpendicular distance from the axis of rotation to a line drawn along the direction of the force is called the __________________________________. Quick (yes you have to do a lab at home) Read through the Quick lab, do the lab, summarize below: 7. Write the equation for Torque in the following space: 8. Is Torque a vector or scalar quantity? 9. Torque is written as negative if the rotation is _______________and positive if the rotation is _______________________________________. 10. Mechanics often us cheater bars to loosen stubborn bolts. A cheater bar is a length of pipe that fits over the handle of a wrench to make the handle longer---How does this help the mechanic? 11. Read through sample E and work through the problem here. Don’t forget about using good problem solving techniques by define givens and unkowns and picking your equation first!!! Do Practice E problems one and three below: Types of Simple Machines Read pg. 258-260 1. What is a machine? 2. What are the six simple machines: (pneumonic devise—Let People Wander When the Party Starts): 3. What is mechanical advantage? 4. What is the ratio for mechanical advantage? 5. The longer the input lever arm is compared to the output lever arm, the _______________________ the mechanical advantage. 6. When using simple machine, even when you reduce the force required for lifting an object, the __________________required to lift it remains the same. 7. What is efficiency? 8. What is the equation for efiiciency? Section Review, Answer problems 1, 2, 3 and 5