Conservation of Energy

In today's class, we went over the questions that was for homework from the book on p. 237 PROBLEMS #s 1, 2, 6, 8, 13, 14, & 21... If you need the answers, I'll just post them maybe tomorrow. After doing the questions, we watched a video about "Conservation of Energy".

Here are the answers for the questions in the sheet that Ms. K. gave us today...

1. What quantities are conserved?
- energy,momentum,angular momentum

2. If energy is conserved, how are things started and stopped?
- Things are started and stopped by work. (the transfer of energy from one type to another)

3. If energy is conserved, why do muscles get tired?
- Muscles get tired because of work.

4. If energy is conserved, why do weights fall?
- Weights fall because of the work.

5. What formula is used to calculate work?
- The formula used to calculate work is W = mgh

6. What is the role of work?
- The role of work is to transfer energy from one place to another.

7. What symbols are used for potential energy?
- The symbols used for potential energy are u or PE.

8. How is potential energy calculated?
- Potential energy is calculated by using the formula u = mgh

9. Is potential Energy by itself conserved?
- No.

10. Which scientist investigated the concept of energy conservation?
- Galileo Galilei

11. What is the formula for kinetic energy?
- The formula for kinetic energy is K = ½ mv²

12. How are kinetic energy and potential energy related?
- E = u + k = constant (Although the energy changed from kinetic to potential and back again, the total amount of energy stays constant.)

13. Who formally stated the law of conservation of energy?
- James Joule

14. Briefly describe this experiment.
- James was calculating how much mechanical energy can be converted to heat.

15. State the two mechanical forms of energy.
- Potential energy and Kinetic Energy

16. Can mechanical energy be tranformed to heat?
- Yes.

17. Is heat a form of energy or is energy a form of heat?
- Heat is a form of energy.


That will be all for today!


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