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3 years ago

Please need help on this

Physics

1 answer:

IRINA_888 [86]3 years ago

3 0

100% correct Answers

Question 1

Which kind of organism obtains energy only from producers?

herbivores

Question 2

Which of the following best describes a population?

members of the same species living in the same place at the same time

Question 3

Which of the following describes soil and temperature in an ecosystem?

abiotic factors

Question 4

A forest fire wipes out all of the plant life in an area, causing the animals to leave. The ground becomes a mixture of soil and ashes. Which order of succession is most likely to occur in the area?

grasses → shrubs → softwood trees → hardwood trees

Question 5

After a town is abandoned, the concrete parking lots remain empty and inactive for hundreds of years. What is the most likely order of ecological succession in that area?

lichens → grass → shrubs → trees

Question 6

The graphs show the trends in biodiversity of land-based life and marine-based life. Choose the answer that best fits the graph.

the sustainability of ecosystems is decreasing regardless of protected areas.

Question 7

Read the passage "Easter Island Palm." Choose the answer below that best fits the problem on Easter Island.

EASTER ISLAND PALM

In the 1400s, the Easter Island palm became extinct due to overharvesting. Reproduction was nearly impossible because islanders introduced rats when they first arrived. These rats ate the Easter Island palm seeds, preventing the Easter Island palm from flourishing. With the disappearance of the palm, the islanders could no longer build the boats they needed for fishing.

a decrease in the temperature, leading to decreased biodiversity

Question 8

The primary reason that the human population has grown rapidly over the past 100 years is that there has been

an increase in food supplies and better access to clean water.

Question 9

Which of the following would cause a decrease in a population's size?

emigration

Question 10

Decisions made by the current generation

can open or limit possibilities of future generations.

Question 11

In order to feed the growing population, scientists have found ways to increase the yield of a crop. What does the term yield mean?

Amount of food produced in an area.

Question 12

Which factor can cause secondary succession?

clear cutting

Question 13

What is the role of a pioneer species in primary succession?

to create the soil

Question 14

The number of rhinoceroses has decreased to near extinction. How are rhinoceroses classified under the Endangered Species Act?

endangered

Question 15

Lions live in groups called prides. Lion populations would most likely fall in which category of population distribution?

clumped

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avanturin [10]

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Another way to understand it is: The distance from which the Earth's orbit appears 1 arcsecond across.

For a parallax angle of 1/2 arcsecond, the distance is 2 parsecs (about 6.52 light years).

1 arcsecond is 1/3600 of a degree, 0.00028 degree.

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3 years ago

A satellite that goes around the earth once every 24 hours (86,400 s) is called a geosynchronous satellite. If a geosynchronous

Olegator [25]

Answer:

42244138.951 m

Explanation:

G = Gravitational constant = 6.667 × 10⁻¹¹ m³/kgs²

r = Radius of orbit from center of earth

M = Mass of Earth = 5.98 × 10²⁴ kg

m = Mass of Satellite

The satellite revolves around the Earth at a constant speed

Speed = Distance / Time

The distance is the perimeter of the orbit

$v=\frac{2\pi \times r}{24\times 3600}$

The Centripetal force of the satellite is balanced by the universal gravitational force

$m\frac{v^2}{r}=\frac{GMm}{r^2}\\\Rightarrow \frac{\left(\frac{2\pi \times r}{24\times 3600}\right)^2}{r}=\frac{6.667\times 10^{-11}\times 5.98\times 10^{24}}{r^2}\\\Rightarrow \left(\frac{2\pi \times r}{24\times 3600}\right)^2=6.667\times 10^{-11}\times 5.98\times 10^{24}\\\Rightarrow r^3=\frac{6.667\times 10^{-11}\times 5.98\times 10^{24}\times (24\times 3600)^2}{(2\pi)^2}\\\Rightarrow r=\left(\frac{6.667\times 10^{-11}\times 5.98\times 10^{24}\times (24\times 3600)^2}{(2\pi)^2}\right)^{\frac{1}{3}}\\\Rightarrow r=42244138.951\ m$

The radius as measured from the center of the Earth) of the orbit of a geosynchronous satellite that circles the earth is 42244138.951 m

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3 years ago

Which feature of a heating curve indicates a change of state?

Andreas93 [3]

A "heating curve" is a graph that shows the temperature of the substance
against the amount of heat you put into it.

For most of the graph, as you'd expect, the temperature goes up as you
add heat, and it goes down as you take heat away. BUT ... While the
substance is changing state, its temperature doesn't change even though
you're putting heat in or taking heat out.

So that part of the graph is a horizontal line.

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4 years ago

Read 2 more answers

A car has an engine which delivers a constant power. It accelerates from rest at time t = 0, and at t = t0 its acceleration is a

olga2289 [7]

Here is the answer of the given problem above.
Use this formula: P = FV = ma*at = ma^2 t
Substitute the values, and therefore, we got m(a0)^2t = m(x)^2 (2t)
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The answer would be a0/sqrt(2).
Hope this answers your question. Thanks for posting.

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4 years ago

A ball, which has a mass of 1.25 kg, is thrown straight up from the top of a building 225 meters tall with a velocity of 52.0 m/

Elena-2011 [213]

First we will find the speed of the ball just before it will hit the floor

so in order to find the speed of the cart we will first use energy conservation

$KE_i + PE_i = KE_f + PE_f$