Educational worksheet on kinetic and potential energy, including classification, real-life examples, formula explanations, and calculation problems.

Let's go through the Kinetic and Potential Energy Worksheet step by step, checking answers, explaining concepts, and ensuring all problems are correctly solved.

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✔ Part 1: Classify as Kinetic (K) or Potential (P) Energy

We classify each situation based on whether energy is due to motion (kinetic) or stored due to position/state (potential).

| # | Situation | Answer | Explanation |
|----|----------|--------|-------------|
| 1 | A bicyclist pedaling up a hill | K | The cyclist is moving → kinetic energy |
| 2 | An archer with his bow drawn | P | The stretched bow stores elastic potential energy |
| 3 | A volleyball player spiking a ball | K | The ball is in motion during the spike |
| 4 | A baseball thrown to second base | K | Moving object → kinetic energy |
| 5 | The chemical bonds in sugar | P | Chemical energy is a form of potential energy |
| 6 | The wind blowing through your hair | K | Air is moving → kinetic energy |
| 7 | Walking down the street | K | Person is in motion |
| 8 | Sitting in the top of a tree | P | Height above ground → gravitational potential energy |
| 9 | A bowling ball rolling down the alley | K | It’s in motion → kinetic energy |
| 10 | A bowling ball sitting on the rack | P | At rest but elevated → gravitational potential energy |

✔ All answers are correct.

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✔ Part 2: Examples from Home

This section asks for real-life examples of kinetic and potential energy at home.

| # | Type | Example | Explanation |
|----|------|--------|-----------|
| 11 | Kinetic | Washing Machine | Spinning drum = motion → kinetic energy |
| 12 | Kinetic | Ceiling Fan | Blades rotating → kinetic energy |
| 13 | Potential | Snow sitting on my roof | Elevated mass → gravitational potential energy |
| 14 | Potential | All the junk on my top shelf in my office | Stored at height → potential energy |

✔ These are good examples. You could also include:
- Kinetic: A running dog, a person walking.
- Potential: A book on a shelf, water in a tank.

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✔ Part 3: What does Kinetic Energy Depend On?

Fill in the blanks:

> ● The more mass an object moves, the more kinetic energy it has.
> ● The greater the velocity of a moving object, the more kinetic energy it has.
> ● Kinetic energy depends on both mass and velocity.

✔ Correct!
Note: The first sentence says "the more ___ an object moves..." — this is slightly awkward phrasing. Better: "The greater the mass of an object, the more kinetic energy it has." But since the answer is mass, it's acceptable.

Also, remember that KE increases with the square of velocity, so speed has a bigger impact than mass.

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✔ Part 4: Word Problems

#### Problem 15: Volleyball Kinetic Energy

> You serve a volleyball with a mass of 2.1 kg. The ball leaves your hand with a speed of 30 m/s. The ball has kinetic energy. Calculate it.

Formula:
$$
KE = \frac{1}{2}mv^2
$$

Plug in values:
$$
KE = 0.5 \times 2.1 \times (30)^2 = 0.5 \times 2.1 \times 900 = 1.05 \times 900 = 945\, \text{J}
$$

✔ Answer: 945 J — Correct!

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#### Problem 16: Baby Carriage Potential Energy

> A baby carriage sits at the top of a hill 21 m high. Mass = 1.5 kg. It has potential energy.

Formula:
$$
PE = mgh
$$

Where:
- $ m = 1.5\, \text{kg} $
- $ g = 9.81\, \text{m/s}^2 $
- $ h = 21\, \text{m} $

$$
PE = 1.5 \times 9.81 \times 21 = 1.5 \times 206.01 = 309.015\, \text{J}
$$

✔ Rounded to two decimal places: 309.02 J
But you wrote 309.015 J — technically correct, but usually rounded to 309.02 J.

So:
$$
PE = 1.5 \times 9.81 \times 21 = 309.015\, \text{J} \approx \boxed{309.02\, \text{J}}
$$

✔ Close enough; your work is correct.

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✔ Final Review & Summary

All answers on the worksheet are correct and well-reasoned.

#### Key Concepts Recap:

- Kinetic Energy (KE): Energy of motion → depends on mass and velocity²
- Formula: $ KE = \frac{1}{2}mv^2 $
- Potential Energy (PE): Stored energy due to position or state
- Gravitational PE: $ PE = mgh $
- Other types: Elastic, chemical, etc.

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✔ Final Answers Summary:

1. K
2. P
3. K
4. K
5. P
6. K
7. K
8. P
9. K
10. P

11. Kinetic: Washing Machine
12. Kinetic: Ceiling Fan
13. Potential: Snow on roof
14. Potential: Junk on shelf

KE depends on: mass, velocity, and both mass and velocity

15. $ KE = 0.5 \times 2.1 \times 30^2 = 945\, \text{J} $ ✔
16. $ PE = 1.5 \times 9.81 \times 21 = 309.015\, \text{J} $ ≈ 309.02 J ✔

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✔ Well done! The worksheet is fully completed correctly. Let me know if you'd like a printable version or want to explore more energy problems!