Explain how we can estimate the geological age of a planetary surface from its number of impact craters.
Fill in the blank(s) with the appropriate word(s).
Answer: Even though impacts still occur today, the vast majority of craters formed during the bombardment period that ended around 3.8 billion years ago. A surface region that is still saturated with craters must have remained essentially undisturbed for the last 3.8 billion years. In contrast, a surface region that has few craters indicates that the original craters must have been "erased" by other geological processes since then.
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Phil stands at rest with both feet on a scale that reads 500 N. When he gently lifts one foot, the scale reads
A) less than 500 N. B) 500 N. C) more than 500 N.
If a sound level increases by 20 dB, the intensity increases by a factor of _______.
a. one thousand b. one hundred c. ten d. ten thousand
The ______________ temperature scale has no negative readings
Fill in the blank(s) with correct word
The force on a 3.00-kg object as a function of position is shown in the figure
If an object is moving at 2.50 m/s when it is located at x = 2.00 m, what will its speed be when it reaches x = 8.00 m? (Assume that the numbers on the graph are accurate to 3 significant figures.) A) 3.25 m/s B) 3.70 m/s C) 4.10 m/s D) 2.90 m/s E) 4.50 m/s