1. Homework Due Read & Study Ch 11; Ch 11 vocab Tonight’s HW Read & Study 11.1 - 11.4 – Do #1- 12 p. 165 Do Now Take a POGIL; put aside Grab a clicker and get ready for your Ch 11 pre assessment! Chapter 11, Lesson 1: April 15 & 16, 2013

2. Suppose you try to push open the door below 3 times. First, you push by the HINGE (see then ‘x’). Then, you push in the middle. Finally, you push by the handle. WHICH IS EASIEST? 1. 2. 3.

3. Can the same torque be exerted from different forces? 1.YES 2.NO 3.IMPOSSIBLE TO SAY

4. If you cannot exert enough torque to turn a stubborn bolt, would more torque be produced if you fastened a length of rope to the wrench handle as shown? 1.YES 2.NO 3.IMPOSSIBLE TO SAY

5. If an object has a LARGE ROTATIONAL INERTIA, do you think it is easy or difficult to get it to rotate? 1.EASY 2.DIFFICULT 3.IMPOSSIBLE TO SAY

6. You roll a hollow disk and a solid disk down the same ramp. You start them from the same height at the same time. Which reaches the bottom first? 1.Solid disk 2.Hollow disk 3.Not enough information to say

7. The 3 batons below have the SAME mass, but the mass is distributed differently. The 1 st baton has most of the mass close to the handle. The 2 nd baton has most of the mass far from the handle. The 3 rd baton has the mass evenly distributed from the handle. Which is easiest to balance? 1. 2. 3.

8. On to the POGIL! CHECK IN AT STOP SIGNS! We are NOT going over as a class – PLEASE check in with a teacher as a group! Stopping with AT LEAST 10 minutes left for a clicker exit!!! If you work efficiently, we may have time to give back your quizzes today…if not, next class

9. Suppose you try to push open the door below 3 times. First, you push by the HINGE (see then ‘x’). Then, you push in the middle. Finally, you push by the handle. WHICH IS EASIEST? 1. 2. 3. Door 3 – bigger lever arm, so you can push with less force and still get the same torque! Countdown 10

10. Can the same torque be exerted from different forces? 1.YES 2.NO 3.IMPOSSIBLE TO SAY F x LA = Torque = F x LA Countdown 10

11. If you cannot exert enough torque to turn a stubborn bolt, would more torque be produced if you fastened a length of rope to the wrench handle as shown? 1.YES 2.NO 3.IMPOSSIBLE TO SAY The rope doesn’t change the lever arm! You need a stronger person (more force), or a bigger wrench (bigger lever arm)! Countdown 10

12. If an object has a LARGE ROTATIONAL INERTIA, do you think it is easy or difficult to get it to rotate? 1.EASY 2.DIFFICULT 3.IMPOSSIBLE TO SAY More R.I., more RESISTANT to change in rotation! If it’s at rest, it REALLY wants to stay at rest! If it’s rotating, it REALLY wants to keep rotating! Countdown 10

13. The 3 batons below have the SAME mass, but the mass is distributed differently. The 1 st baton has most of the mass close to the handle. The 2 nd baton has most of the mass far from the handle. The 3 rd baton has the mass evenly distributed from the handle. Which has the GREATEST rotational inertia? 1. 2. 3. The farther the bulk of the mass is from the turning axis, the MORE R.I. there is!!! Countdown 10