She can put chalk in vinegar as the vinegar will disintegrate the chalk chemically demonstrating chemical changes. But for physical changes she can break the chalk into small pieces by smashing it with something or her hand.
Answer:
a = change in v / change in time
= (5.2 - 11) / 3.1
= -1.87 m/s^2
Explanation:
C. A 1200kg car is going 15m/s
It is determined by the nature of the green light. Because lasers create light at almost a single frequency, green laser light would appear as a thin line of pure green. Other sources of "green" light emit light at a variety of frequencies, including yellow and blue, resulting in a strong green band in the center that fades into blue-green and yellow-green at the borders.
For example, here’s a graph of the spectrum of a green LED, showing the color range: Attachment #1
and here’s a graph of the transmission spectra of several standard photographic filters, including green: Attachment #2
Learn more about the color spectrum:
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