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o-na [289]
3 years ago
12

About three billion years ago, single-celled organisms called cyanobacteria lived in Earth’s oceans. They thrived on the ocean’s

abundance of ___ , which they used during the process of photosynthesis. Much later, this process allowed organisms, such as fish, to survive by extracting dissolved ___ from ocean waters.
a. oxygen
b.carbon dioxide
c. nitrogen
Physics
2 answers:
quester [9]3 years ago
6 0

The first blank is carbon dioxide, second one is oxygen

pickupchik [31]3 years ago
3 0
I think its Oxygen. 
ancient cyanobacteria produced Earth's first oxygen-rich atmosphere, which allowed the eventual rise of eukaryotes. T<span>he chloroplasts of eukaryotic algae and plants are derived from cyanobacteria</span>
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The length of a bicycle pedal arm is 0.152 m, and a downward force of 118 N is applied to the pedal by the rider's foot. What is
Veseljchak [2.6K]

Answer:8.968 N-m

Explanation:

Given

Length of arm=0.152 m

Downward force=118 N

angle made by arm with vertical=30^{\circ}

Force can be divided into two components

It's sin component will contribute towards torque while cos component will not contibute

Torque =Fsin30\times L

T=118\times sin30\times 0.152

T=8.968 N-m

5 0
3 years ago
Vanessa made a list comparing the differences between the outer coverings in plants and animals, but she made a mistake. Read th
GaryK [48]

The skin is NOT a reproductive organ and the spines attract predators are the incorrect statements.

<h3>Why the list is incorrect?</h3>

The list is incorrect because skin is not a reproductive organ and the spines do not attract predators towards each other. Skin protects the body from the outer environment whereas the spines repel the predators from the plant body.

So we can conclude that the skin is NOT a reproductive organ and the spines attract predators are the incorrect statements.

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8 0
2 years ago
Pls help 100 points plssssssss
natima [27]

Answer:

d

Explanation:

8 0
2 years ago
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Each of the space shuttle's main engines is fed liquid hydrogen bya high-pressure pump. Turbine blades inside the pump rotateat
kvasek [131]

Answer:

a) a= \frac{4 \pi^2 (0.02 m)^2}{0.00162 s}=9.74 \frac{m}{s^2}

b) k = \frac{9.8}{9.74}=1.006

Explanation:

Part a

For this case we can begin finding the period like this:

T= \frac{1}{w} =\frac{1}{617 rad/s}=0.00162 s

Then we know that the centripetal acceleration is given by:

a= \frac{v^2}{r}

And the velocity is given by:

v=\frac{2\pi r}{T}

If we replace this into the acceleration we got:

a = \frac{(\frac{2\pi r}{T})^2}{r}= \frac{4 \pi^2 r}{T^2}

And we can replace the values and we got:

a= \frac{4 \pi^2 (0.02 m)^2}{0.00162 s}=9.74 \frac{m}{s^2}

Part b

For this case we want to find a value of k such that:

a= k 9.8

Where a = 9.74, so then we can solve for k like this:

k = \frac{9.8}{9.74}=1.006

8 0
3 years ago
List at least 10 derived units of some physical quantities.​
Artist 52 [7]

Answer:

pressure, stress pascal N/m2

energy, work, quantity of heat joule N·m

power, radiant flux watt J/s

electric charge, quantity of electricity coulomb -

8 0
3 years ago
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