Ask question

Ask question

All categories

notsponge [240]

3 years ago

7

A farmer wants to expand his fields, but only has hills left. He is worried about water erosion because of the rate at which wat

er is pulled down the hills during rainstorms. What can this farmer do to reduce the water erosion he fears?
a.Rotate his crops so that there is permanent groundcover.
b.Reshape the hills with terraces.
c.Use contour plowing on the hills.
d.Install silt fences at the bottom of the hills.

1 answer:

Aleks04 [339]3 years ago

7 0

Answer:

Reshape the hills with terraces

Explanation:

It is the best way of preventing water eroding when it comes of doing agriculture on hills

You might be interested in

When backpacking in the wilderness, hikers often boil water to sterilize it for drinking. Suppose that you are planning a backpa

Pavlova-9 [17]

Answer:

2.104 L fuel

Explanation:

Given that:

Volume of water = 35 L = 35 × 10³ mL

initial temperature of water = 25.0 ° C

The amount of heat needed to boil water at this temperature can be calculated by using the formula:

$q_{boiling} = mc \Delta T$

where

specific heat of water c= 4.18 J/g° C

$q_{boiling} = 35 \times 10^{3} \times \dfrac{1.00 \ g}{1 \ mL} \times 4.18 \ J/g^0 C \times (100 - 25)^0 C$

$q_{boiling} = 10.9725 \times 10^6 \ J$

Also; Assume that the fuel has an average formula of C7 H16 and 15% of the heat generated from combustion goes to heat the water;

thus the heat of combustion can be determined via the expression

$q_{combustion} =- \dfrac{q_{boiling}}{0.15}$

$q_{combustion} =- \dfrac{10.9725 \times 10^6 J}{0.15}$

$q_{combustion} = -7.315 \times 10^{7} \ J$

$q_{combustion} = -7.315 \times 10^{4} \ kJ$

For heptane; the equation for its combustion reaction can be written as:

$C_7H_{16} + 11O_{2(g)} -----> 7CO_{2(g)}+ 8H_2O_{(g)}$

The standard enthalpies of the products and the reactants are:

$\Delta H _f \ CO_{2(g)} = -393.5 kJ/mol$

$\Delta H _f \ H_2O_{(g)} = -242 kJ/mol$

$\Delta H _f \ C_7H_{16 }_{(g)} = -224.4 kJ/mol$

$\Delta H _f \ O_{2{(g)}} = 0 kJ/mol$

Therefore; the standard enthalpy for this combustion reaction is:

$\Delta H ^0= \sum n_p\Delta H^0_{f(products)}- \sum n_r\Delta H^0_{f(reactants)}$

$\Delta H^0 =( 7 \ mol ( -393.5 \ kJ/mol) + 8 \ mol (-242 \ kJ/mol) -1 \ mol( -224.4 \ kJ/mol) - 11 \ mol (0 \ kJ/mol))$

$\Delta H^0 = (-2754.5 \ \ kJ - 1936 \ \ kJ+224.4 \ \ kJ+0 \ \ kJ)$

$\Delta H^0 = -4466.1 \ kJ$

This simply implies that the amount of heat released from 1 mol of C7H16 = 4466.1 kJ

However the number of moles of fuel required to burn $7.315 \times 10^{4} \ kJ$ heat released is:

$n_{fuel} = \dfrac{q}{\Delta \ H^0}$

$n_{fuel} = \dfrac{-7.315 \times 10^{4} \ kJ}{-4466.1 \ kJ}$

$n_{fuel} = 16.38 \ mol \ of \ C_7 H_{16$

Since number of moles = mass/molar mass

The mass of the fuel is:

$m_{fuel } = 16.38 mol \times 100.198 \ g/mol}$

$m_{fuel } = 1.641 \times 10^{3} \ g$

Given that the density of the fuel is = 0.78 g/mL

and we know that :

density = mass/volume

therefore making volume the subject of the formula in order to determine the volume of the fuel ; we have

volume of the fuel = mass of the fuel / density of the fuel

volume of the fuel = $\dfrac{1.641 \times 10^3 \ g }{0.78 g/mL} \times \dfrac{L}{10^3 \ mL}$

volume of the fuel = 2.104 L fuel

3 0

3 years ago

Anything with mass creates gravity, but the amount of gravity is proportional to the amount of mass.

gayaneshka [121]

Answer:

Explanation:

The amount of gravity is directly proportional to the amount of mass of the objects and inversely proportional to the square of the distance between the objects. Gravity is a force that increases the velocity of falling objects - they accelerate.

6 0

3 years ago

Read 2 more answers

If a compound contains a poly atomic ion then what type of compound is it A. Convalent Compound B. Ionic Compound

den301095 [7]

Answer:

B. Ionic Compound

Explanation:

An ionic compound is that compound which contains a positively charged ion called CATION and a negatively charged ion called ANION. The cation loses or transfers electrons to the anion, hence, making the former (cation) positive and the latter (anion) negative.

A polyatomic ion is an ion that contains more than one type of atom e.g OH-, NO3²-, CO3²- etc. A polyatomic ion usually has an overall charge formed from the charges of the individual atoms that makes it up. For example, in OH-, the overall charge is -1.

Since a polyatomic ion can have an overall positive or negative charge, it must enter a reaction with another ion that complements it i.e. a negative polyatomic ion will react with a positive ion to neutralize its charge. Hence, this forms an IONIC COMPOUND. This is why most compounds with polyatomic ions are IONIC COMPOUNDS.

For example, CaCO3 is an ionic compound formed when Ca²+ (cation) reacts with the polyatomic anion: CO3²-

5 0

3 years ago

A. When glucose molecules link up what substance do they form?

alexgriva [62]

Answer:

Explanation: b

7 0

3 years ago

Read 2 more answers

2 H2 + O2= 2 H2O

AVprozaik [17]

Answer:

the answer is 4.0moles

Explanation:

1mole of O2 produce 2moles of H2O/x mole will produce 8.0moles of H2O then the answer is 4.0moles.

3 0

3 years ago