Electricity and Magnetism
As you are folding the laundry, you find a sock stuck to a T-shirt. Which statement best explains why the sock and T-shirt are stuck together?
A. they are electromagnets
B. They have neutral charges
C. They have opposite charges
D. They have the same charge
C
With electricity and magnetism remember the phrase "Opposites Attract!"
Ruki watched her friends jumping off a low diving board and a high diving board. She observed that the splashes form the high dive were much bigger. Why is that?
Faster objects have more energy than slower objects. The high diver hit the water with more speed than the low diver. So, more energy transferred to the water. That is what made the bigger splash.
Energy moves through ___________.
Waves.
Hector and his mom were making cupcakes. She poured some white solid sugar into boiling water and stirred. It eventually disappeared! What happened?
All substance are made of particles too small to be seen. In this case the water dissolved because it is soluble.
Color, phase, hardness, reflectivity, electrical conductivity, thermal conductivity, and solubility are all examples of what?
Properties of Matter
Belle holds a magnet across the room from a refrigerator. She lets go, and the magnet drops to the floor. Why isn't the magnet attracted to the refrigerator door?
A. The refrigerator door cannot hold magnets.
B. Magnetic force weakens over distance.
C. Electricy in the iar blocks the magnetic field.
D. Another magnet is pulling the refrigerator magnet away.
B. Magnetic Force weakens over distance.
Remember: The further away the magnet, the weaker the pull!
How does energy change when two objects collide?
The speed and direction of both objects will change. Think about kicking a soccer ball. Your foot swings forward and hits the ball. The ball shoots forward, but your foot also slows down and bounces off the ball.
Name the types of waves.
sound, water, light and radio.
Hector's mom accidentally left a pot of water boiling on the stove. Hector saw the pot was completely empty, and he turned off the heat. What happened to the water?
The water evaporated. It turned from a liquid to a gas and can no longer be seen.
Some materials make new substances when they combine with other materials. This kind of change is called what?
A chemical change
True or False:
Magnetism is the force that pushes objects apart or pulls them together.
TRUE
When energy transfers where does it go?
Energy is conserved as it transfers. It always changes: For example, motion may change into heat or sound. But, it never disappears.
What does amplitude represent?
A. Whether the wave is light or sound.
B. The energy carried by the wave.
C. How fast the wave travels.
D. How long each wave is.
B. The energy carried by the wave.
Amplitude and wavelength are features of all waves. Amplitude shows the energy of a wave.
What are the three phases of matter and what is the definition of each one?
A solid- has definite shape and definite volume.
A liquid- has definite volume but no definite shape.
A gas- has no definite shape and no definite volume.
You can tell a chemical change has occurred when you observe what happening.
bubbles being given off, solids form when two liquids are mixed (milk and vinegar), the combination produces a new smell, the new substance changes color (ammonia and phenothalein)
Electricity and magnetism are related.
TRUE
They both come from charged particles called electrons.
What is mechanical energy?
Motion
What is wavelength?
The length of a wave.
What is the difference between a mixture and a solution?
A mixture is a combination that doe snot change the ingredients. The particles of the substances in a mixture do not change and can go back to their regular state.
A Solution is a type of mixture. In a solution a substance has dissolved into another.
Which of the following creates a new substance?
A. salt dissolving
B. water evaporating
C. a match burning
D. water and dirt combining to make mud
C a math burning- Combustion- producing heat and light.
What is the flow of charged particles or charges from one place to another called?
Electricity
Imagine rubbing a piece of sandpaper back and forth quickly over a piece of wood. What will most likely happen to the wood?
A. It will light up.
B. It will become warm.
C. It will start to hum.
d. It will begin to spark.
B. It will become warm
When two objects rub against one another, friction changes some of the mechanical energy.
A high level of friction could cause the wood to spark and light up. BUT, sandpaper cannot transmit that much friction. So, A and D are incorrect.
Sandpaper on wood makes a scratching sound, not a hum. So C is incorrect.
During training at the police academy, new officers learn about sending and obtaining confidential information through coded messsages carried by sound waves. Which instrument would be useful for practice?
A. Camera
B. Badge
C. Radio
D. Flashlight
C. Radio
Maya adds 4 grams of ice to a glass of 8 grams of liquid water. After 4 hours the ice cubes have melted. If no water has evaporated what is the total mass of the water at this point?
12 grams
Rex mixed a pitcher of lemonade. He poure da cup of sugar into a pitcher of water and stirred. Eventually, all the white sugar crystals disappeared. Which statement best describes what happened?
A. Sugar crystals broke apart and became water.
B. The sugar evaporated adn disappeared into the air
C. The sugar particles reacted with the water and made a new substance.
D. The particles making up sugar crystals are too small to be seen.
D. the particles making up the sugar crystals are too small to be seen.