All energy comes from the Sun. In what forms has this solar energy come to us to allow us to live and to operate our society? Research the ways that the Sun’s energy is turned into a form that we can use. After we use the Sun’s energy, where does it go? Explain.

What is the difference between fundamental and derived units?

A fly hitting the windshield of a moving pickup truck is an example of a collision in which the mass of one of the objects is many times larger than the other. On the other hand, the collision of two billiard balls is one in which the masses of both objects are the same. How is energy transferred in these collisions? Consider an elastic collision in which billiard ball $m_{1}$ has velocity $\boldsymbol{v}_{1}$ and ball $\boldsymbol{m}_{2}$ is motionless. a. If $m_{1}=m_{2}$, what fraction of the initial energy is transferred to $m_{2}$? c. In a nuclear reactor, neutrons must be slowed down by causing them to collide with atoms. (A neutron is about as massive as a proton.) Would hydrogen, carbon, or iron atoms be more desirable to use for this purpose?

The apparent magnitude of a star is the measure of its brightness as seen by someone on Earth. The smaller the apparent magnitude, the brighter the star. Use the apparent magnitudes table below.

Which star listed is the brightest?

Consider the following debate between two students. Student 1: I think a star with an apparent magnitude number of -2.0 would look brighter than a star with an apparent magnitude number of +1.0. Student 2: I disagree . You don't understand the number scale for apparent and absolute magnitude. The bigger the number the brighter the star. So the +1.0 star would look brighter than the -2.0 star. Do you agree or disagree with either or both of the students? Explain your reasoning.

The full Moon has an apparent magnitude of -12.6 , and when Mars is at its brightest in the night sky, its apparent magnitude is +2.0.

Which object will look brighter from Earth, the full Moon or Mars? How do you know?

The full Moon has an apparent magnitude of -12.6, and when Mars is at its brightest in the night sky, its apparent magnitude is +2.0. a) Which of the two objects has the bigger apparent magnitude number? b) Which object will look brighter from Earth, the full Moon or Mars? How do you know? c) If a new object were discovered ,that looked even dimmer from Earth than Mars does , make up a possible apparent magnitude number for it.

Which value, apparent magnitude, or absolute magnitude, do you think:

tells us about the object's actual brightness?

If two stars are the same size, but one has a higher surface temperature, which star, if either, is more luminous? Explain your reasoning.

If two stars have the same surface temperature and are the same size , which star, if either , is more luminous? Explain your reasoning.

If you use two hot plates of different sizes, can you assume that the hot plate that can cook a large pot of spaghetti first is at a higher temperature? Which lettered example above supports your answer?

If you use two hot plates at the same temperature , can you assume that the hot plate that can cook a large pot of spaghetti first is larger? Which letter example above supports your answer?

Imagine you are comparing the ability of electric hot plates of different sizes and temperatures to fully cook two identical large pots of spaghetti. Note that all the pots are as large as the largest hot plate. The shading of each hot plate is used to illustrate its temperature. The darker the shade of gray the cooler the temperature of the hot plate.

For each pair of hot plates shown below, circle the one that will cook the large pot of spaghetti more quickly. If there is no way to tell for sure, state that explicitly.

If you use two hot plates of the same size, can you assume that the hot plate that can cook a large pot of spaghetti first is at the higher temperature? Which lettered example above supports your answer?