Light
Light displays properties of both a [what?] and a [what?].
Wave and particle
What are the two pieces of evidence of the Big Bang Theory?
Expansion and uniformity.
What is the definition of a machine?
A machine makes work easier by multiplying your force.
A ratio is a comparison between two quantities, a proportion is when two or more ratios are equal.
What is the word for the part of the bridge that you move across?
The deck.
Longer wavelength corresponds to [higher/lower?] frequency and [higher/lower?] energy.
Lower, lower
What two factors influence the force of gravity between two objects? Give an example from the solar system.
Mass and distance. Planets further away from the sun orbit more slowly.
What are the differences between force, work, and power?
A force is a push or a pull; work is a force exerted over a distance; power is a measure of how much work is done in a given amount of time.
Why does the rule of thumb have to do with multiplicating by 10?
Because the ratio between the length of your arm and the distance between your eyes about 10.
What does deformation mean? Explain the two kinds of stresses that deform bridges.
Deformation is changing the shape, and compression and tension deform bridges: compression by pushing in and trying to buckle, tension by pulling out and trying to snap.
What should you see if you shine white light through a perfect red filter on a lemon, and why?
Nothing, because a perfect red filter would only allow red light through, but a lemon absorbs red light.
What is a solstice, why does it occur, and how is it related to the seasons?
A solstice is the longest day in the year in a given hemisphere. It occurs because the Earth is tilted, and it is occurs when it is summer in a given hemisphere because one hemisphere is maximally tilted towards the sun.
How do you calculate efficiency, and what will it always be in the real world?
Output work/input work = output force (weight) * output distance (often height) / input work * input distance.
Always less than 1.
What is water pressure proportional to, and why?
Why is an arch bridge more stable than a beam bridge?
The arch shape resists compression (since it's bent in the opposite direction) and directs the force out to the abutments on land.
Why is blue at one end of the rainbow and red on the other?
Because blue light has the highest frequency and so refracts and scatters most, while red light has the lowest frequency and so refracts and scatters least.
Why do scientists theorize that the universe has been expanding? (Use the words "Doppler Effect" and "Redshift.")
Scientists observe redshift of the emission spectra of stars, which looks like all the light waves are "stretched." The Doppler Effect is when an observer perceives longer wavelengths from an object moving away. So maybe the reason we observe longer wavelengths from stars is because they are moving away from us.
What is the trade-off involved in using an inclined plane, and how is that trade-off seen in the other machines?
Using an inclined plane requires less force over more distance. The same is true of a wedge, just vertical instead of horizontal; a screw is less force, more turns with less force; a pulley is less force, more pulling; a wheel and axle is less force, bigger radius; a lever is less force longer rigid bar.
Why might Fibonacci numbers be common in nature? (Need a thorough answer)
Since the ratio between them is irrational, Fibonacci numbers are more likely to help an organism maximize the spacing of things like leaves to that they never perfectly overlap.
Why are suspension bridges stronger than beam bridges?
They transfer the force of stress to cables and thereby to the land.
How does light move through a vacuum?
Moving electricity generates a magnetic field and moving magnetism generates an electric field, so an electromagnetic wave generates its own electromagnetic field.
Nuclear fusion is the fusion of atomic nuclei into a bigger nucleus; it occurs in stars due to the force of gravity; and it produces energy in the form of heat and light.
How does friction cause machines to "lose work to heat"?
A machine “loses work to friction” when some of the effort force gets used to “jiggle” molecules, heating up the materials instead of moving the object.
Explain this quote: "A fractal is a picture of a process that created it." Give an example.
Fractals are created through a process that repeats on itself. The branching of veins in our lungs, for example, shows that a branching process to create an organ of maximum surface-area/volume ratio.
Why are triangles a strong shape, and how is this used in bridge-engineering?
Triangles cannot bend (deform), they can only break, so they are used to support bridges in the form of trusses, which DISSIPATE the forces of compression and tension.