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3 years ago

Which pulley system will allow the armchair to be lifted with the least amount of effort?

Chemistry

2 answers:

lyudmila [28]3 years ago

7 0

ANSWER:

I think it's C

Explanation:

I just learned about this in science class and I'm pretty sure you need 2 pulleys to make it easier to pull

guapka [62]3 years ago

5 0

Answer:

Option D.

Explanation:

Option D. Since tension experimented by the rope is equal to one sixth of the weight of armchair.

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A river with a flow of 50 m3/s discharges into a lake with a volume of 15,000,000 m3. The river has a background pollutant conce

spin [16.1K]

Explanation:

The given data is as follows.

Volume of lake = $15 \times 10^{6} m^{3}$ = $15 \times 10^{6} m^{3} \times \frac{10^{3} liter}{1 m^{3}}$

Concentration of lake = 5.6 mg/l

Total amount of pollutant present in lake = $5.6 \times 15 \times 10^{9} mg$

= $84 \times 10^{9}$ mg

= $84 \times 10^{3}$ kg

Flow rate of river is 50 $m^{3} sec^{-1}$

Volume of water in 1 day = $50 \times 10^{3} \times 86400 liter$

= $432 \times 10^{7}$ liter

Concentration of river is calculated as 5.6 mg/l. Total amount of pollutants present in the lake are $2.9792 \times 10^{10} mg$ or $2.9792 \times 10^{4} kg$

Flow rate of sewage = $0.7 m^{3} sec^{-1}$

Volume of sewage water in 1 day = $6048 \times 10^{4}$ liter

Concentration of sewage = 300 mg/L

Total amount of pollutants = $1.8144 \times 10^{10} mg$ or $1.8144 \times 10^{4}kg$

Therefore, total concentration of lake after 1 day = $\frac{131936 \times 10^{6}}{1.938 \times 10^{10}}mg/ l$

= 6.8078 mg/l

$k_{D}$ = 0.2 per day

$L_{o}$ = 6.8078

Hence, $L_{liquid}$ = $L_{o}(1 - e^{-k_{D}t}$

$L_{liquid}$ = $6.8078 (1 - e^{-0.2 \times 1})$

= 1.234 mg/l

Hence, the remaining concentration = (6.8078 - 1.234) mg/l

= 5.6 mg/l

Thus, we can conclude that concentration leaving the lake one day after the pollutant is added is 5.6 mg/l.

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3 years ago

david’s mom wants to calculate how much it will cost to drive from los angeles, ca, to san francisco, ca. gas costs $4.00 a gall

grin007 [14]

She needs to know the distance from LA to SF.

Call that distance x. Then you can calculate the cost from:

# of gallons consumed: x miles / 38 miles/ gallon = (x/38) gallons

After that,

cost = # gallons * cost per gallon = (x/38) gallons * 4 $/gallon = 4x/38 $

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3 years ago

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Katarina [22]

Answer:

a covalent would be the two that are nonmetals

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3 years ago

what mass of chromium (III) sulfide is produced from the reaction of 13.2 g of sulfur with excess chromium?

Andreas93 [3]

Answer: Cr2S3

Explanation:

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3 years ago

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What did Ernest Rutherford discover? How was his model different from Thomson’s?

s2008m [1.1K]

Answer:

thomson developed the chocolate chip method which was the identification of the electrons in the core of an atom. Rutherford discovered that the core was only positive and that the electrons were floating outside of the core.

Explanation:

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3 years ago