Converting Energy
What converts electric energy into heat energy? Toaster, Fan, Lamp, or Radio?
Toaster
A path along which electric charges can flow is called what?
Circuit
Insulator
An object that has thermal energy can lose some of that energy. Which answer describes an example of the thermal energy of a material decreasing?
A eggs cooking in a pan
B water freezing into ice
C snow melting in the spring
D a ball bouncing on the floor
water freezing into ice
Ariana uses balloons to investigate static electricity. What will happen when she brings two positively charged balloons close to each other?
The balloons will move apart.
On hot summer days, Rudy uses a fan in his bedroom. What energy transformation most helps the fan to do its job when he turns it on?
Electrical energy into energy of motion
If one light bulb in a series circuit does not work, what happens to the rest of the lights?
They wont work, the circuit is broken.
Material that carries electric charges
Conductors
What form of energy cooks food in a solar cooker?
A chemical energy
B electrical energy
C light energy
D mechanical energy
Light Energy
Mr. Washington mixed iron filings with sand. Then, he asked his students to separate the iron filings from the sand. What is the best tool to use to separate the iron filings from the sand?
A magnet
Batteries store energy in the form of chemical energy. The chemical energy can be converted into electrical energy, which can be used to operate a pencil sharpener. Which diagram best shows the energy conversions that help the boy sharpen the pencil?
A. electrical → chemical → heat
B. chemical → electrical → sound
C. chemical → electrical → motion
D. motion → electrical → chemical
chemical → electrical → motion
What is the difference between open and closed circuits?
Closed circuits are unbroken so electricity will flow and in an open circuit, the electricity will not flow.
The outside of Camelia’s extension cord is made of rubber. What is the reason rubber is used here?
It is a good insulator
Kailea conducts an investigation. She sets a pat of butter under a lamp and turns the lamp on. Kailea returns after 5 minutes and finds the butter has melted.
The butter melted because the lamp produced light and heat energy.
Why do two socks sometimes stick together in a dryer?
Electrons move from one sock to another.
Bill’s mom likes to listen to the radio in the kitchen while she is making dinner. What energy transformation does she notice when she turns on the radio?
Electrical energy into sound energy
Copper is used to make electrical wires. Why is copper a good material for electrical wires?
It allows an electric current to flow freely.
Name two metals that would be good conductors.
silver, gold, aluminum, iron, bronze, mercury, or copper
Rubbing your hands together warms them up. If you put lotion on your hands before you rub them together, how do you think this would change the results?
The lotion would make your hands slippery, so they would produce less heat.
Which is true about how a charged object interacts with a neutral object?
A The charged object becomes uncharged.
B The neutral object remains neutral.
C They repel each other.
D They attract each other.
They attract each other.
When Zan sat down to do her homework, she turned on a desk lamp. What energy transformation occurs when a desk lamp is turned on?
electrical energy into light and heat energy
Quentin makes a circuit tester using a battery, a light bulb, and wire. Then he tests objects (nail, ribbon, toothbrush, or toothpick) to see which ones close the circuit between the metal screw hooks and light the light bulb. Which of the following objects closes the circuit?
Nail
Aldo wanted to know whether tap water or saltwater is a better conductor of electricity. He attached a battery and an instrument to measure electrical flow. He tested the tap water and then added salt to make saltwater and ran his test again. Aldo observed that electricity was not flowing when he used tap water, but it was flowing when he used saltwater. What conclusion can Aldo draw based on these observations?
Saltwater is a good conductor.
What is heat energy also known as?
Thermal energy
Curtis uses a wool cloth to give a balloon a negative charge. What will happen when he holds the balloon near the wall?
The balloon will stick to the wall because a negatively charged object is attracted to an uncharged object.