The heterotroph hypothesis is an attempt to explain (1) how Earth was originally formed (2) why simple organisms usually evolve into complex organisms (3) why evolution occurs very slowly (4) how life originated on Earth

What is ozone? How might Earth be affected if there were no ozone layer in the stratosphere?

Applying Ideas How would seasons be different if Earth was not tilted on its axis?

a. What is a satellite? b. What causes satellites to stay in orbit rather than falling toward Earth? c. a projectile is thrown with enough velocity to orbit Earth. What would happen if the projectile were thrown with a greater velocity?

A solar eclipse occurs when the Moon passes between the Earth and the Sun. Use a diagram to show why some areas of the Earth see a total eclipse, other areas see a partial eclipse, and most areas see no eclipse

A $2150 \mathrm{~kg}$ satellite used in a cellular telephone network is in a circular orbit at a height of $780 \mathrm{~km}$ above the surface of the earth What is the gravitational force on the satellite? What fraction of this force of the satellite's weight is at the surface of the earth?

Calculate the gravitational potential energy of a $9.50\mathrm{~kg}$ mass on the surface of the Earth.

(a) A stone is thrown upward with a certain speed on a planet where the free-fall acceleration is double that on Earth. How high does it rise compared to the height it rises on Earth? (b) If the initial speed were doubled, what change would that make?

The frequency of light reaching Earth from a particular galaxy is $15 \%$ lower than the frequency the light had when it was emitted. Is this galaxy moving toward or away from Earth? Explain. Give your answer as a fraction of the speed of light.

Does the Earth do any work on the Moon as the Moon moves in its orbit?

Write down logical representations for the following sentences, suitable for use with Generalized Modus Ponens:

• a. Horses, cows, and pigs are mammals.
• b. An offspring of a horse is a horse.
• c. Bluebeard is a horse.
• d. Bluebeard is Charlie’s parent.
• e. Offspring and parent are inverse relations.
• f. Every mammal has a parent.

The orbital revolution of the Moon about Earth takes about 27.3 days and is in the same direction as Earth's rotation (24 h). Use this information to show that high tides occur everywhere on Earth every 12 h and 26 min.

The temperature at the surface of the Sun is approximately $5700 \mathrm{~K}$, and the temperature at the surface of the Earth is approximately $290 \mathrm{~K}$. What entropy change occurs when $1000 \mathrm{~J}$ of energy is transferred by radiation from the Sun to the Earth?

The same hemisphere of the moon always faces Earth. Thus, the motion of the moon about Earth for a given time interval can be modeled by a rotation. The center of the rotation is the center of Earth. The angle of rotation is determined by the time interval, given that one journey of the moon around Earth takes about $27 \frac{1}{3}$ days.

What rotation is modeled by the motion of the moon?

A. a circle rotating about its center

B. a circle rotating about a point

C. 2 circles rotating around each other

D. a circle rotating around a circle