Homework: Torque and Simple Machines

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:
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