Basic forms of energy

Alice walked outside on a cold day and forgot her gloves. She rubbed her hands together quickly. Soon, her hands felt warm. When Alice rubbed her hands together quickly, she used __________ to produce heat energy.

• burning

• friction

• solar energy

• mixing things together

Answer explanation

When Alice rubbed her hands together, she created friction between them. This friction generates heat energy, warming her hands. Therefore, the correct answer is friction.

Tags

NGSS.4-PS3-2

Nora's family went camping. Which way did her family MOST LIKELY produce heat energy while camping?

• by burning

• by friction

• by electricity

• by mixing things

Answer explanation

Nora's family most likely produced heat energy by burning, as this is a common method for generating heat while camping, such as using a campfire or stove. The other options are less practical in a camping context.

Chemical energy stored is in the bonds of compounds and molecules and can be transformed through a chemical reaction. Which does NOT represent an example of chemical energy?

• batteries

• food

• gasoline

• sunlight

Answer explanation

Sunlight does not represent chemical energy as it is a form of electromagnetic energy. In contrast, batteries, food, and gasoline store energy in chemical bonds, which can be released during chemical reactions.

The picture below shows wind turbines in a field. When the wind blows, it causes the wind turbines to spin. When wind turbines spin, they produce electrical energy. What kind of energy causes the wind turbines to spin?

• mechanical energy

• electrical energy

• sound energy

• light energy

Answer explanation

The wind causes the blades of the wind turbines to move, which is a form of mechanical energy. This mechanical energy is what makes the turbines spin and ultimately generates electrical energy.

Look at the list of activities below.

1. 
   

2. a hot-air balloon flying

3. 
   

4. a grasshopper jumping

5. 
   

6. a traffic signal lighting up

7. 
   

8. a basketball bouncing

9. 
   

10. a pair of hands clapping

11. 
    

12. a solar-powered clock ticking

13. 
    

14. a laptop computer beeping

Which activities use thermal energy?

• activity 6

• activities 3 and 4

• activity 1

• activities 5 and 6

Answer explanation

Activity 1, a hot-air balloon flying, uses thermal energy as it relies on heated air to rise. The other activities do not primarily involve thermal energy in their processes.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-3

NGSS.MS-PS3-4

Alex plucks one of the tightest strings on a guitar. This string produces a high-pitched sound. Next, he plucks a string that is not as tight. It vibrates more slowly and produces a lower-pitched sound.

What is MOST LIKELY true about the loosest string on the guitar?

• It vibrates the fastest and produces the highest-pitched sound on the guitar.

• It vibrates the fastest and produces the lowest-pitched sound on the guitar.

• It vibrates the slowest and produces the lowest-pitched sound on the guitar.

• It vibrates the slowest and produces the highest-pitched sound on the guitar.

Answer explanation

The loosest string vibrates the slowest due to less tension, resulting in a lower frequency. This is why it produces the lowest-pitched sound, confirming that the correct choice is that it vibrates the slowest and produces the lowest-pitched sound.

Tags

NGSS.MS-PS4-1

NGSS.MS-PS4-2

Energy! It is everywhere. Scientists describe energy as the ability to do work. Energy causes change. See if you can identify the different forms of energy in the pictures.

Choices: Light energy, Wind energy, Sound energy, Heat energy, Electrical energy

• Wind energy

• 
• Sound energy

• 
• Electrical energy

• 
• Light energy

• 
• Heat energy

• 

What property of light is causing the phenomenon of the landscape and clouds appearing in the lake?

• refraction

• absorption

• reflection

• darkness

Answer explanation

The landscape and clouds appear in the lake due to reflection. Light from the scenery bounces off the water's surface, creating a mirror-like image, which is why we see the surroundings reflected in the lake.

Tags

NGSS.MS-PS4-2

What property of light is causing the phenomenon of the landscape and clouds appearing in the lake?

Which statement supports your answer?

• Light changes direction when it passes from one material to a different material.

• Light is split into different colors when it passes through a prism.

• Light bounces off of surfaces such as the lake.

• When light is blocked by an object, it creates shadows. 

Answer explanation

The landscape and clouds appear in the lake due to the reflection of light. The correct choice states that light bounces off surfaces like the lake, creating the visual effect of the surroundings being mirrored.

Tags

NGSS.MS-PS4-2

Which type of energy shown on the diagram is an example of mechanical energy?

• battery

• bicycle

• guitar

• sun

Answer explanation

A bicycle is an example of mechanical energy because it involves the movement of parts (wheels, pedals) to perform work. In contrast, a battery stores chemical energy, a guitar produces sound energy, and the sun emits radiant energy.