The wavelength

of the wave is 160 m, and this is the distance between two consecutive crests. The boat is located at a crest of the wave, this means that the first trough is located 80 meters from the boat (because the distance between a crest and a trough is half the wavelength).
The speed of the wave is

so the time the boat takes to reach the first trough is
<span>The unknown substance is silver.
I don't see a list of available substances, but let's see if there's something reasonable available that will match. First, let's calculate the density of the unknown substance. Density is mass per volume, so
273 g / 26 mL = 10.5 g/mL
Looking up a list of elements sorted by density, I see the following:
10.07 Actinium
10.22 Molybdenum
10.5 Silver
11.35 Lead
And silver at 10.5 g/ml is a very nice match for the unknown substances' density of 10.5 g/ml.</span>
The correct answer is "Humidity". good luck!
<span><span>1.
</span>Question : What part of the plant that transport
water from its root to its leaves.
The answer is the stem. The stem connects the plant’s root and leaves, it is
responsible for transporting water that is absorbed by the root going to the
leaves, it is also responsible for transporting nutrients absorbed with the
leaves coming from the sun or any nutrients going to the roots to make is grow
faster and healthy. Stem is the one that connects leaves and root and the one
the does the transporting job.</span>