# HP Cycle 22

## 1/19 - 1/24

F 1/19

M 1/22

T 1/23

W 1/24

### 🟩 5: M 1/22 - 📄 Hooke's Law Lab

Today, we’ll investigate how springs behave and learn about Hooke’s Law through an exploratory lab. In the lab, you’ll try to answer the following questions:

Handout:  📄 Hooke's Law Lab

Homework Finish the 📄 Hooke's Law Lab worksheet.  It will be collected tomorrow during class.  Quiz on energy conservation problems next class - Monday, January 22nd Wednesday, January 24th.

### 💚❗ 5: W 1/24 - 📖elastic potential energy

Quiz on energy conservation problems TODAY.

Today, we'll start by thinking about reviewing Hooke's Law Fe = -kx where x is the displacement from a spring's equilibrium position.  We'll learn that for certain springs that obey Hooke's Law, the elastic force is proportional to the amount of stretch or compression.  The proportionality constant k is called the "spring constant" and is measured in units N/m.  The elastic force is a conservative force.  The negative sign in Hooke's Law indicates that the force is in the opposite direction to the displacement from the equilibrium position, but when we plug into our ΣF statement, we'll just use the magnitude |Fe|= kx since the direction will be accounted for in the + or - before the force.

Then, we'll learn that to find the energy stored in the spring, we need to take the area under this curve which gives us:  Ue = ½ kx2.  We'll include this potential energy into our before & after diagrams by including a third question:

Finally, we'll review what we've learned about Hooke's Law and elastic potential energy by doing problems from 📖 Mastering Physics "Ch 10 - elastic potential energy" #24, 25, 48.

Optional Extra Practice:  PedersonScience.com.

HomeworkHooke's Law Lab assessment on Thursday, January 25th Friday, January 26th.  Finish the above 📖 Mastering Physics problems by Thursday, January 25th at 10pm.  Write out a solution for the third video below and upload it to ✏️Google Classroom also by Thursday at 10pm.

If for some reason you missed class today or you need a review, check out the following videos from Dan Fullerton:

Watch examples during time 7:45-11:05 only, unless you want more practice with other conservation of energy problems.

Finally, here's a more complex example like what you'd see on a test. (Think about how you'd do this with our Before & After diagram and our conservation of energy equation. Remember that the spring force is a conservative force.)  Write out your solution to this problem and submit it to ✏️ Google Classroom by Thursday at 10pm.