AT Cycle 6
10/11 - 10/14
🔴❗ 1: M 10/11, 🟡❗ 3: M 10/11 - simple torque problems
QUIZ on energy and momentum TODAY!
After the quiz, we'll have an opportunity to look over the last assessment.
Then, we'll work on some simple torque problems. Finish page 1 of the Torque Packet.
❤️ 1: Th 10/14, 🟨 3: T 10/12 lab - torque meterstick lab
Today, we'll apply the concepts of torque and static equilibrium to find the mass of a meterstick. If you still need help here, watch the following video.
Lab Safety: Be careful when handling metersticks that you do not swing into someone else. Make sure that you handle masses with care and do not drop off the table as they could hurt you if they fall on you. Always follow your teacher's directions to use the equipment exactly as outlined.
Handout: Torque Meterstick Lab
In case you miss class, you can do the above lab by using some materials you have at home:
a ruler (at least 30cm) or meterstick or a long uniform stick that you can measure or put evenly spaced markings on. (Whatever you use should be as inflexible as possible, a metal or flexible ruler will probably not work.)
something thin that you can balance the ruler on (I used a round pencil taped to my desk, but you could perhaps even use your finger).
some coins or washers of known mass (the heavier your ruler, the heavier/more things you'll need) - you'll need probably 8 of the same type.
some tape to secure the coins or washers to the ruler.
Simulation Alternative: PhET Balancing Act - Part 1 can be done using this simulation if you do not have the materials. You'll have to partner with someone in your lab group for part 2 if you don't have physical materials.
With any time remaining, we'll try the Hard Torque Problems for practice with static equilibrium. We will continue working on these next hour as well.
Answers: Hard Torque Problems
1. T3 = 250N, m = 40kg
2. T2 = 3700N, Fhy = 2350N down, Fhx = 1850N right
3. T2 = 600N, Fhx = 520N left, Fhy = 50N up
4. T1 = 289N, Fhx = 289N right, Fhy = 350N up
5. Fwall = 727N, Ff = 727N, Fground = 1230N
6. 51.3 degrees (there's a typo, it should say "minimum angle")
Homework: Finish your write up for the Torque Meterstick Lab. It will be collected on paper at the beginning of each class. Make sure that you have already watched the following video on Torque Equilibrium Problems. Also, read the following webpage on Vector Multiplication. Remember that to calculate torque, we use a cross product. Review the right hand rule.