Explain the history of Earth's moon
What will be an ideal response?
The history of Earth's moon since its formation is dominated by a single fact-the Moon is small, only one-quarter the diameter of Earth.The Apollo moon rocks are the source of information about the timing of events during the Moon's history. For example, they show that the Moon must have formed in a mostly molten state. Planetary geologists now refer to the exterior of the newborn moon as a magma ocean. Denser materials sank toward the center, and low-density minerals floated to the top to form a low-density crust. In this way, the Moon partly differentiated.The second stage, cratering and basin formation, began as soon as the crust solidified, and the older highlands show that cratering was intense for approximately 0.7 billion years-during the heavy bombardment at the end of the Solar System's period of planet building. The Moon's crust was shattered, and the largest impacts formed giant multiringed basins hundreds of kilometers in diameter.The third stage, slow surface evolution, was limited both because the Moon cooled rapidly and because it lacks water. Flooding on Earth included water, but the Moon has never had an atmosphere and thus has never had liquid water. With no air and no water, erosion is limited to the constant bombardment of micrometeorites and rare larger impacts.
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a. parallel to the magnetic axis b. anti-parallel (opposite direction) to the magnetic axis c. random d. perpendicular to the magnetic axis
Which of the following types of electromagnetic radiation has the highest frequency?
a. x-rays b. visible light c. radio d. gamma-rays e. infrared radiation
What is the highest order (the m value) of the complete visible spectrum (390 nm to 710 nm) that can be obtained with a grating having 300 lines/mm?
a. 5 c. 8 b. 9 d. 4
During an adiabatic compression, a volume of air decreases to 1/4 its original size. Calculate its final pressure if its original pressure was 1 atm. (Assume the air behaves like an ideal gas with ? = 1.4.)
a. 7.0 atm b. 5.6 atm c. 3.5 atm d. 2.2 atm e. 0.14 atm