Questions tagged [homework]

If your question is part of your high school or college/university homework, please use this tag. Do not use this as the only tag on a question. It signifies that instead of a direct answer, care should be taken to explaining the steps to the solution, preferably sticking to just giving helpful, conceptual hints. This tag may be applied to questions which are not homework but are similar to a homework problem.

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24
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3answers
11k views

Why is there a seasonal cycle to the amount of CO2 in the atmosphere?

I'm doing some homework on the increase of $\mathrm{CO}_2$ in the atmosphere. On one of the graphs it shows the amount of $\mathrm{CO}_2$ peaks in May and has a low in November. Why is this? Shouldn't ...
10
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1answer
3k views

Lake inflow-outflow problem

The evaporation from a lake is to be calculated by the water balance method. Inflow to the lake occurs through three small rivers, A, B and C. The outflow occurs through the river D. Calculate ...
9
votes
1answer
1k views

A parcel of air in an isothermal layer

I'm having a bit of trouble figuring out a solution to this problem: There is an isothermal layer of air which has a temperature of 0 °C extending from the surface to 1 km height. A parcel is 0.5 °C ...
9
votes
1answer
254 views

Simplest formula of a calcium phosphate mineral?

I had a homework question: Given the formula: $$\ce{Ca}_x\ce{(PO4)}_y\ce{OH}$$ Find the lowest possible values of $x,y$ and state (look up) the mineral name. Based on the anion charges ...
8
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4answers
139 views

How do I find the horizontal pressure level that divides the atmosphere into 2 layers of equal mass?

Surface pressure given is p = 1000 hPa. (the temperature along the atmosphere is constant (T = −10 °C; hydrostatic equilibrium assumed). I tried using the hypsometric equation to find the height of ...
7
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3answers
707 views

Oxygen isotope ratio and Glaciers

The question is basically: During the Cretaceous there were no continental ice sheets. The ratio of O-18/O-16 in sea water was: a) Higher than today b) Lower than today The answer ...
7
votes
1answer
221 views

How to calculate hydrostatic equilibrium?

I'm trying to solve the following problem. The sea level in the past was 200 m higher than today. The seawater became in isostatic equilibrium with the ocean basin. what is the increase in the depth $...
6
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2answers
3k views

What is the shortest path between two points on Earth's surface?

I am a Math student and don't know about longitude and latitude. This question was asked in CSIR-NET Mathematics. Please help me to solve it. Two points $A$ and $B$ on the surface of the Earth have ...
6
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2answers
1k views

Interpreting a geological map

I have a homework question that I'm stuck on, I have attempted interpreting this map but am not sure if I have to correct interpretation. What is the youngest/oldest rock in the geological ...
6
votes
1answer
822 views

Plotting a mineral stability diagram

I'm trying to figure out how to plot the stability of 4 minerals — $\ce{CaCO3}$, $\ce{CaSO4}$, $\ce{CaMg(CO3)2}$, and $\ce{CaMg3(CO3)4}$ — with axes of $\mathrm{ln}\,a_{\ce{Mg^{+2}}}$ vs $\mathrm{ln}\,...
6
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2answers
656 views

Take all the CO2 in the atmosphere and put it into a layer on the surface of earth, how thick would the layer be?

I teach a Middle School (year 8) Geometry course and have a student attempting to answer this question. My assumptions: earth's radius is $3959 \text{ mi}$ earth is a sphere There is approximately $3 ...
6
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1answer
1k views

Maps and Faults

I'm having trouble determining the type of fault represented on this map. What type of fault is represented on this map? What is the fault orientation? What does this mean?, Do I do this by working ...
6
votes
1answer
393 views

Define components of mineral assemblage?

Given the a mineral assemblage with the minerals $$cp (\ce{CuFeS_2}), bn (\ce{Cu_5FeS_4}), cc (\ce{Cu_2S}), mt (\ce{Fe_3O_4}), py(\ce{FeS_2})$$ where cp, bn, mt are in contact, and py, cp, bn, cc are ...
6
votes
1answer
138 views

The environments of particular deposits

I came across this question in my text book: "During a visit to a mountainous area, students noticed a high mountain consists of 3 different parts: The top of the mountain consists of fossiliferous ...
6
votes
1answer
109 views

Identifying trichroic crystal systems

An unknown mineral shows three distinct pleochroic colours. Explain what observations you need to make in order to decide which crystal system it belongs to. If it has three pleochroic colours this ...
5
votes
3answers
584 views

The fertility of the soil

I came across this question in my book, it says: The fertility of the soil increases when there is a lot of ....... in it. The choices to fill the space were: Nitrogen - nodular bacteria - ...
5
votes
2answers
498 views

Number of tectonic plates

I came across a question asking what's the number of tectonic plates in this illustration: I don't know on which basis we count the tectonic plates. And I'm confused because I think they are 5 but ...
5
votes
1answer
8k views

How to calculate residence time for an element in a reservoir?

The residence time for an element in a reservoir can be calculated by the reservoir size at steady state divided by the inflow or outflow rate. Given the following diagram, I need to calculate the ...
5
votes
1answer
754 views

Calculating magnetic declination for a non-axial dipole field

I'm trying to answer the following question: Compute the inclination and declination of the magnetic field that would be observed in Boulder, Colorado (40°N, 105°W) if the Earth’s field ...
5
votes
1answer
118 views

Carbon dioxide and ocean acidification based on temperature

For our assignment, we are required to analyse and compare the $\ce{CO2}$ level (in both ocean and air) of two different sites. Theoretically, shouldn't the $\ce{CO2}$ level of a colder region (e.g., ...
5
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0answers
93 views

Dating fluvial terraces with $^{10}\rm{Be}$

I've completed part A of the question below. Dating fluvial terraces with $^{10}\rm{Be}$ One way to determine the age of an alluvial deposit is to collect a series of samples from a range of depths, ...
4
votes
1answer
256 views

A sedimentary rock with only minerals

In my text book I came across this multiple-choice question A sedimentary rock consists of only minerals and lacks fossils, it could be classified as: i) a clastic sedimentary rock ii) a ...
4
votes
1answer
2k views

How can I normalize this chemical analysis to a mineral with 3 cations?

$\ce{FeO}$ = 70 wt% $\ce{TiO2}$ = 30 wt% The molecular weight given of $\ce{FeO}$ = 72, and the mw of $\ce{TiO2}$ = 80. The first step I did was divide each wt% by their molecular weights to get a ...
4
votes
1answer
592 views

How and why humidity and vapour pressure change as a parcel of air with an unchanging amount of water vapor rises, expands, and cools

I know that a parcel of air can rise, cool and create clouds and rain but I'm struggling to understand how: absolute humidity relative humidity actual vapour pressure saturation vapour pressure ...
4
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0answers
87 views

Are there any books, websites, etc. that have many practice problems for Skew-T diagrams and the atmospheric sciences in general?

I am asking because my Intro to Atmospheric Science class (lectures, labs, and the book) has not provided any practice examples of Skew-T diagrams, Coriolis force calculations, LCL (liquid ...
3
votes
2answers
2k views

How do I convert between different east longitude coordinates?

I have two datasets that represent longitude in different ways. The first represents longitude as degrees from east to 180, but then as negative east so that I have a series which looks like: ...
3
votes
1answer
397 views

The free oxygen (O$_2$) in the atmosphere is largely a result of what process?

Does it come from a)atmospheric lightning and ozone dissociation. b)meteorite impacts early in the earth's geological history. c)Paleozoic volcanic activity. d)photosynthetic processes. e)...
3
votes
1answer
504 views

Help determining virtual geomagnetic pole

Magnetic measurements have been made on some lavas found at 60ºN and 90ºW. The inclination angle is 37º. If the horizontal direction of magnetism of these lavas is due west, calculate the position of ...
3
votes
5answers
842 views

Where are the oldest igneous rocks found?

I'm trying to catch up on my homework for earth science, but I'm having a difficult time searching for an answer to my question.
3
votes
1answer
355 views

Relative dating of intrusion

I am quite new to geology and have a realtive dating problem which I am a bit unsure of. I know very well the principle of superposition, principle of cross-cutting, etc., but am still a little bit ...
3
votes
1answer
187 views

Differentiate a rock and mineral

How to differentiate between a rock and a mineral by merely looking at it as a thumb rule?
3
votes
1answer
995 views

How to determine if this fault is normal, sinistral?

Studying for an exam tomorrow and stumped on this question (parts d and e). The region show in Map 2 consists of a series of sedimentary strata that have been tilted and then eroded, producing an ...
3
votes
1answer
2k views

How do you calculate the elevation at which clouds will form (lifting condensation level)?

I have a parcel of air at 30°C with a dew point temp of 15°C. It goes up and then back down a mountain 4km in height. Assuming the normal and dry adiabatic lapse rates apply, and an ELR=7.5°C/km, ...
3
votes
0answers
311 views

Puzzle using relative dating principles

This isn't directly looking at a real life ecological example kind of thing, but it requires knowledge of relative dating, so I thought I would come here. Here is what was told: -"Worms" (curved ...
2
votes
2answers
138 views

Making clouds for science project

This is about a group project for our science class and we've decided to do a physical model on clouds. We could use liquid nitrogen and hot water to demonstrate the formation of the clouds and we ...
2
votes
2answers
152 views

How to graph gravity as a function of depth, given radius and density?

I need to do this for a planet that has uniform density, and a planet that has two layers. For the first part, I was given that the density was 550 kg/m³, so I made one column in an Excel spreadsheet ...
2
votes
1answer
536 views

The apparent path of the sun

An American College Test sample question asks: Based on the shadow directions in these experiments, which of the following best describes the difference between the apparent path of the Sun as seen ...
2
votes
1answer
93 views

When and where is the atmospheric greenhouse effect strongest?

Is the greenhouse effect stronger in the ice covered area or in the equator? Also is it stronger during winter or summer? I am thinking it is stronger in the Ice covered area and during winter because ...
2
votes
1answer
117 views

Result of deterioration of vegetation

I had this question in my previous exam, it says: Deterioration of vegetation resulted by overgrazing results in...... 1.desert encroachment. 2.change in climate. I had to choose 1 or 2 ...
2
votes
0answers
68 views

Optical Thickness of the Atmosphere

Homework question: Show that the absorption optical thickness of the atmosphere at pressure $p$ (i.e., between $p$ and the top of the atmosphere) as a function of the mixing ratio of the ...
1
vote
1answer
78 views

Dynamic meteorology - calculating air temperature based off falling air

I'm not sure if this is the correct place to ask this. Basically I have an exercise in dynamic meteorology that is set up like this: 1 kg of dry air is falling with a constant speed of 0.5 cm / s ...
1
vote
1answer
194 views

Easy homework questions about seasons and daytime

The following homework assignment is supposed to be easy, but there seems to be information missing from the questions asked (or at the very least knowledge from OP). At which width circle does the ...
1
vote
1answer
662 views

What equation should I use in this isostasy problem?

I have this problem, and I am not sure where to start. The only Airy equation in my text is $r_1= \frac{h_1 \cdot p_u}{p_s - p_u}$. This doesn't seem to apply, or if it does it isn't obvious. Is ...
1
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0answers
28 views

Finding out actual dip and dip direction of refractor

We have two traveltive curves for first arrivals (direct and refracted) from a dipping refractor in the forward and reverse directions along a profile line. my question is: Is there a logical way (non-...
1
vote
0answers
146 views

Modification of an air mass

If an air mass that exists in North America starts moving south west or south east what kind of modification will affect it and how would you characterize it in it's final state? My answer is that it ...
1
vote
0answers
28 views

Agricultural self sufficiency after yellowstone eruption?

Given a 440 acre farm running roughly 200 acres of Crops and 40-50 head of cattle,in the secondary ash zone within the lake of the ozarks reigon of Missouri, how viable would survival be relying on ...
1
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0answers
26 views

what are some limitations for using meteorites as evidence for the Earth's age?

I'm currently doing a question at the moment which is: Evaluate the usefulness and limitations of evidence provided by meteorites of Earth's age. I'm having trouble finding some limitations at the ...
1
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0answers
46 views

Pyrite oxidation

How much pyrite has to be oxidized to produce a sulfate concentration of 15 mM? If the solution initially has a pH of 8, roughly what would the pH drop to if there is no buffering of acidity?
1
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0answers
52 views

How can the hydrosphere be properly used to reduce the load on the lithosphere [closed]

The earth is made up of 70% hydrosphere and 30% lithosphere.The space of lithosphere is continually used and it seems there is a threat to a balance ecosystem.Describe how the hydrosphere can be make ...
1
vote
0answers
33 views

Residence time for another planet [closed]

This is a question about residence time for another planet with the following information below: When we arrive on the second habitable planet, we discover that it is also exactly like Earth, except ...