96 terms

Multi Unit Exam (Scientific Method, Energy, Waves)

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Medium
any substance that a wave moves through
Pitch
the highness or lowness of a sound
Reflection
the bouncing back of a wave after it strikes a barrier
Refraction
the bending of a wave as it enters a new medium at an angle
Transmission
the passage of a wave through a medium
Absorption
the disappearance of a wave into a medium
Mechanical Wave
waves that transfer energy through matter
Crest
the highest point of a wave
Trough
the lowest point of a wave
How would you measure the wavelength of a transverse wave?
the distance from one wave crest to the very next crest
How would you measure the wavelength of a longitudinal wave?
the distance from one compression to the next
How would you measure the amplitude of a transverse wave?
the distance between a line through the middle of a wave and a crest or trough
How would you measure the amplitude of a longitudinal wave?
how tight the compressions are in a medium
How do you measure the frequency of a wave?
the number of waves passing a fixed point in a certain amount of time
How are frequency, wavelength and pitch related?
As frequency increases, wavelength decreases, and pitch increases.
How are amplitude, frequency and wavelength related?
Changes in amplitude do not change the frequency or wavelength. For example, if I am speaking in a low pitch, I can be making a low pitched loud sound or a low pitched soft sound.
What changes the amplitude of a wave?
Energy!
What is a transverse wave?
the direction the wave moves is perpendicular to the direction of the disturbance
What is a longitudinal wave?
the wave travels in the same direction as the disturbance
Why do objects appear the color they are?
Objects have the color of the wavelength of light they REFLECT. For example, if an object is blue, that means that it reflects the blue wavelength and absorbs the other visible light wavelenths.
What must occur in order for you to see something?
Light waves must reflect off of the object
Why does refraction occur?
When light hits different mediums at an angle, they pass through the mediums at different speeds.
What produces transverse waves?
light (EM waves)
What produces longitudinal waves?
sound
What is an example of a sound wave being reflected?
an echo
What is an example of a light wave being reflected?
seeing your reflection in a mirror
What causes sound?
Compressions in molecules caused by vibrations
Can sound travel through a vacuum?
No. Sound must travel through matter and there is no matter in vacuums.
What is a wave?
a disturbance that transmits energy through matter and space
What are some waves that move outward from their disturbance?
Seismic waves, waves on the ocean
What can sound travel through?
Matter - anything that has mass and volume
If a wave is created in the middle of the ocean, does the water from the middle of the ocean move all the way to the shore with the wave?
No! The energy is what transfers!
What is the law of conservation of energy?
energy cannot be created or destroyed, only transformed
Are sound and light forms of kinetic or potential energy?
kinetic!
What does radiant energy deal with?
waves from the electromagnetic spectrum
What is the most common form of nuclear energy?
Nuclear fusion and fission that take place in stars like the Sun!
What energy transformations occur to produce sugar through photosynthesis?
nuclear energy in the sun is transformed into heat and light energy which is transformed into chemical energy in the plant when the sugar is produced
What is an electromagnetic wave?
a disturbancee that transfers energy through a field. Also known as EM waves.
Sound waves are mechanical waves. Light is a form of radiation. What is different about how they travel through a medium?
A mechanical wave requires matter and cannot move through a vacuum. Radiation can move through a vacuum.
What kinds of frequencies are in the EM spectrum?
Radio waves, microwaves, infrared light, visible light, ultraviolet light, x rays, and gamma rays
What kind of EM frequency deals with heat waves?
infrared light
What kind of EM frequency deals with light that we see from the Sun?
visible light
What makes the different types of waves in the EM spectrum?
Their wavelengths and frequencies
When trying to identify the independent variable, what question do you ask yourself?
We did everything the same in each trial except ______________?
When trying to identify the dependent variable, what question do you ask yourself?
What did we measure?
What is a control group?
The group that is left "normal" or "typical", it is the group we compare our results to
What is a constant?
Factors in an experiment that are left the same in each trial.
How many independent variables can you have in one experiment? Why?
Only one! If you change more than one thing, then you will not know which variable affected the results.
John wondered which brand of dish soap worked the best. So, he washed half of his dishes with Joy and half of his dishes with Dawn. He then compared how clean each dish soap made the dishes. What is the independent variable?
the type of dish soap
John wondered which brand of dish soap worked the best. So, he washed half of his dishes with Joy and half of his dishes with Dawn. He then compared how clean each dish soap made the dishes. What is the dependent variable?
the cleanliness of the dishes

NOT "which dishes are cleaner"
Rachel learned about how to make electromagnets using wires, batteries, and nails. She wanted to see if the number of batteries used would increase the strength of the magnet. So, Rachel created different electromagnets. First using 1 battery, Rachel tried to see how many paper clips the magnet could pick up. Then, she repeated the process with 2 and 3 batteries. For each electromagnet, she counted how many paper clips the magnet could hold. What is the independent variable?
the amount of batteries
Rachel learned about how to make electromagnets using wires, batteries, and nails. She wanted to see if the number of batteries used would increase the strength of the magnet. So, Rachel created different electromagnets. First using 1 battery, Rachel tried to see how many paper clips the magnet could pick up. Then, she repeated the process with 2 and 3 batteries. For each electromagnet, she counted how many paper clips the magnet could hold. What is the dependent variable?
the strength of the magnet or the amount of paper clips held

**NOT "which magnet holds the most"
John wondered which brand of dish soap worked the best. So, he washed half of his dishes with Joy and half of his dishes with Dawn. He then compared how clean each dish soap made the dishes. What would be some of the "constants" he would need in his experiment?
The length of time he scrubbed, the amount of each soap used, the dirtiness of the dishes, etc
What is the unit for energy?
Joules
What is kinetic energy? Give an example.
the energy of motion. ex) a chair falls off of a table
What is gravitational potential energy? Give an example.
stored energy based on an object's size and position. ex) a book sits on top of a table.
What is elastic potential energy?
stored energy created by an object changing shape. ex) stretching a rubber band or coil/spring
YOU NEED TO KNOW WHAT ALL OF THE LAB TOOLS LOOK LIKE. YOU WILL NEED TO BE ABLE TO IDENTIFY THEM IN THE LAB. YOU HAVE A LAB EQUIPMENT SHEET IN YOUR BINDER AND THEY ARE ALL ON THE ANSWER KEY TO THE REVIEW/STUDY GUIDE.
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What is the purpose of a Bunsen burner?
To heat or burn objects
What is the purpose of an eyedropper or pipet?
To slowly drop liquids one drop at a time
What is the purpose of a stirring rod?
To stir chemicals in a lab
What is the purpose of a crucible?
To heat matter or evaporate liquids
What is the purpose of a fleaker?
To measure volume or hold liquids that need to be poured
What is the purpose of a rubber stopper?
To plug or "stop" a flask
What is the purpose of a flask?
To measure volume or hold liquids that need to be "capped"
What is the purpose of tongs?
To grasp hot or dangerous objects in a lab
What is the purpose of a ring stand?
To hold up containers (i.e. over a Bunsen burner)
What is the purpose of a mortar and pestle?
To crush (a.k.a smooosh) objects
What is the purpose of a beaker and a graduated cylinder?
to measure volume
What is the purpose of a scale and a triple beam balance?
to measure mass
How do you know if something is a fair test?
There is only one independent variable.
How many independent variables can you have in one experiment? Why?
There can only be one independent variable because otherwise you would not know which factor is affecting the data.
If the velocity that two objects are moving are the same, finish the following relationship statement:

As mass increases, kinetic energy _____________.
increases
If the mass of two objects are the same, finish the following relationship statement:

As velocity increases, kinetic energy _____________.
increases
What is magnetic potential energy?
energy stored due to the position of a magnet, energy is stored when the magnet repels or attracts
What is chemical potential energy?
the energy stored in chemical bonds that hold compounds together. If bonds are broken, energy is released!
What is nuclear potential energy?
the potential energy stored in the nucleus of an atom. The sun uses nuclear energy!
What is electrical energy?
energy used by the movement of electrons
energy that comes from waves in the electromagnetic spectrum. Ex) Light rays, x rays, radio waves and gamma rays
What is sound energy?
energy created from vibrating particles
What is thermal energy?
the energy an object has due to the motion of its molecules (This means temperature is a measure of kinetic energy!)
How can you measure the kinetic energy of the particles in a substance?
By measuring temperature.
Write a relationship statement that described the relationship between the distance of a paper clip to a magnet and the amount of magnetic potential energy stored.
As distance decreases, magnetic potential energy decreases.
Write a relationship statement that describes the relationship between the distance an object is from the ground and the amount of gravitational potential energy stored.
As distance increases, gravitational potential energy increases.
What is conduction?
heat transfer when two objects are touching, molecules bump into each other
the transfer of heat through electromagnetic rays
What is convection?
heat transfer through fluids (gas/liquid), hot less dense fluid rises and cold, more dense fluid sinks in a cycle
At the beach, it is easy to walk on the grass, but when you walk on the sand, it can feel very hot. Why is this?
Different types of matter transfer heat differently.
Describe the energy transfer that would allow a baseball to increase its kinetic energy when being hit by a bat.
Energy was transferred FROM the bat TO the ball causing it to speed up.
Light travels through air at 200 million m/s, glass at 300 million m/s, and water at 226 million m/s. Between which two materials would light bend the most.
Between air and glass because there is the biggest difference in speed.
What causes refraction?
light travels in straight lines except at the surfaces of transparent mediums where light bends
Why can you see through a window?
light is transmitting through it
What is the difference between green and violet?
They are both light waves, but they have different wavelengths and frequencies.
How would you increase the brightness of visible light?
Increase the amplitude
Why is grass green?
Because grass reflects the green wavelength and absorbs all of the other wavelengths of visible light
Why do our eyes refract light?
Because they are made of different transparent mediums