Answer:The height of First Copy is 20 cm.
Step-by-step explanation:
Given:
Original Height = 25 cm
First copy is reduce to 80% of Original height.
Therefore to find the height of first copy can be find out by multiplying 80 with original height and then dividing by 100.
∴ Height of First Copy =
Hence Height of first copy is 20 cm
Now Another copy is reduce to 85% of First Copy.
Therefore to find the height of another copy can be find out by multiplying 85 with first copy height and then dividing by 100.
∴ Height of Another Copy =
Hence Height of Another copy is 17 cm
Explanation:
What is the correct number of digits to express a measurement
Answer:
Examples of measured numbers: The diameter of a coin, such as 10.2 mm. The weight of an object, such as 8.887 grams. The length of a pen, such as 12 cm.
Explanation:
Answer:
It completely depends on what you are measuring, what instrument you are using, and the uncertainty associated with your measurement.
Explanation:
When expressing a measurement, there is always going to be a part that you know, and a part that you guess. They both make up known numbers collectively called significant figures (commonly shortened to "sig figs"). For instance, imagine you are measuring the length of a pencil. Let's say it is a typical ruler with divisions of 0.1 cm (picture for reference). You measure the pencil, and to your eyes it looks like it is about 9 cm and 5 small tick marks (so, 0.5 cm), so we'll call that 9.5 cm. Now, this is a known value, so you are certain that it is a least 9.5 cm. However, it may be true that there is one more decimal place that can be known. The general rule is that you want to add one more uncertain digit to the rightmost side of the number, and how many digits depends on the divisions of the instrument. Our ruler has divisions of 0.1 cm (the small tick marks), and so we will go one more place out, and add another digit. Now, let's say our eyes are pretty good, so let's say it's 9.5 cm, and then add that one uncertain digit, a 0 to the smallest division of 0.1, so, 0.10. The final measurement we record is 9.50 cm. Now, it may seem like we are simply guessing or even being unreasonable in our assessment of how long this pencil is. I can promise you that not knowing the actual measurement of this pencil will not make a spaceship crash because of a specification that was not the "right measurement". For those life-or-death measurements, much more precise measurement machines are used; this is just a pencil. Also, it would be unreasonable to say that it is 9.500000 cm or 9.500001 cm. We do not have that kind of certainty with this ruler, only divisions of 0.1 cm, so we can only estimate out to one more decimal place.
In short, find the smallest division of a ruler or whatever device (like a chemical beaker) you are using, and then add one uncertain digit to the end of that. If it's 0.1 cm, then add one digit to that. (example: 5.6 --> 5.63; 3 because that is what it looks like on the ruler). If it's 1 cm, then add an extra .1, so the measurement is 1.1 cm. And of course, it's not always cm you are using, that was just an example. Best of luck!
What is a lone pair?
A. Two pairs of electrons that form a double bond
B. Two atoms that have been pushed close to each other
C. A pair of electrons that is not used in bonding
D. A diatomic molecule attracted to no other molecule
Answer:
I BELIEVE IT is c.
Explanation:
The head of a hammer is often made of steel. This makes the head heavy, which helps create a strong force for driving nails. Steel is also strong. The head of a hammer must be strong to resist what force?
A The force of the air resistance on the moving hammer
B The force of the person using the hammer
C The force of gravity pulling down on the hammer
D The force of the nail pushing in the opposite direction
Answer:
A
Explanation:
In simple terms: Hammer goes one way, air goes the other way.
Answer:
d
Explanation:
i took the test
If you have 8.5 moles of water (H2O), how many grams of water do you have?
Answer: i think it is 144.16
Explanation:
can someone help me (╥︣﹏᷅╥)
Water stored in snow and ice can return directly to the atmosphere through the process of sublimation.
((its timed pLEasE
Please select the best answer from the choices provided
T
F
Which two compounds are used in batteries?
sulfuric acid and potassium hydroxide
ammonium hydroxide and nitric acid
potassium hydroxide and nitric acid
sulfuric acid and ammonium hydroxide
Answer:
The chemicals which are electrolytes include: Sodium chloride, chloric acid, nitric acid, potassium nitrate, hydrochloric acid, potassium nitrate, sulfuric acid, sodium hydroxide, magnesium hydroxide and sodium acetate.
Answer:
Sulfuric acid and potassium hydroxide.
Explanation:
These are the two compounds used in car batteries, hope this helps!
SOMEONE HELP PLS ILL GIVE BRAINLIEST AND 19 PT
Sample left = 6.25 g
The percentage = 6.25%
Further explanationGiven
t1/2 = half-life = 3.8 days
t = decay time = 15.2 days
No = initial sample = 100 g
Required
Nt = final sample left
The percentage
Solution
General formulas used in decay:
[tex]\large{\boxed{\bold{N_t=N_0(\dfrac{1}{2})^{t/t\frac{1}{2} }}}[/tex]
Input the value :
[tex]\tt N_t=100.\dfrac{1}{2}^{15.2/3.8}\\\\N_t=100.\dfrac{1}{2}^4\\\\N_t=6.25~g[/tex]
The percentage : Nt/No
6.25 : 100 = 6.25%
Give an example of a chemical reaction during which a single substance breaks
down. *
Answer:
2NaCl(l) => 2Na(s) + Cl₂(g)
Explanation:
Electrolysis of melt NaCl to form sodium (Na) metal and chlorine (Cl₂) gas.
This is a class of reaction called 'Decomposition Rxns'. For what it's worth, there are 6 distinct compound types that undergo breakdown by decomposition. The acronym C O A C H E can help remember them.
C - Carbonates => CaCO₃(s) => CaO + CO₂
O - Oxides of Metals => 2Fe₂O₃(s) => 4Fe°(s) + 3O₂(g)
A - Acids (Oxoacids) => H₂CO₃(aq) => CO₂(g) + H₂O(l)
C - Chlorates, Bromates & Iodates => 2KClO₃(s) => 2KCl(s) + 3O₂(g)
H - Hydroxides => Ca(OH)₂(s) => CaO(s) + H₂O(l)
E - Electrolysis => see above electrolysis of NaCl(l)
Answer:
2NaCl(l) => 2Na(s) + Cl₂(g)
Explanation:
Pls help!!! it’s a timed answer
Answer:
Explanation
whats your question
Which best describes what is represented by images 1 and 2?
Image 1 shows a polymer, and Image 2 shows a monomer.
Image 1 shows a monomer, and Image 2 shows a polymer.
Image 1 shows a macromolecule, and Image 2 shows a synthetic polymer.
Image 1 shows a synthetic polymer, and Image 2 shows a macromolecule.
Answer:
b
Explanation:
im doing a test about it
Answer:
b
Explanation:
5. Why is it necessary to regularly test the pH of pool
water?
Answer:
To ensure that everyone enjoys using your pool, it is important to keep the swimming pool pH levels in balance at all times. If the pH is too high, it could cause skin irritation and corrode metal parts on the pool. If the pH is too low, it could create a situation where the chlorine in the pool isn't as effective.
Explanation:
Answer:
I don't see multiple choice, so I'll answer this based on what I have learned on my free time.
Explanation:
Usually, when a ton of Urine is in a pool, it can throw off the Ph balance, and can even damage human eyes. Trust me, it's happened to me one time. my eyes burned like fire.
i dont know the answer pls help me
Answer:
Unicellular
Explanation:
Unicellular organisms are made up of only a single cell
How many carbon atoms are represented by the model below?
Answer:
3
Explanation:
What are the reactants in the reaction? What are their properties? Perform a quick Internet search, if needed.
The reactants in this reaction are sodium and chlorine. Sodium is a soft, silvery-white metal that is highly reactive. Chlorine is a poisonous greenish-yellow gas that has an odor and combines readily with other elements.
This might be the exact question so you might wanna rephrase it but good luck! :)))
A reactant is a substance that undergoes change during a chemical reaction.
A reaction in a chemical experiment is which takes place when there are mixtures between two or more reactants.
There are about four types of reactions which are:
SynthesisDecompositionSingle replacementDouble replacementPlease note that your question is not complete, therefore, i would give you a general overview to help you.
Some examples of reactants include:
HydrogenSodiumChlorine, etcRead more here:
https://brainly.com/question/12056938
I will need help plz thank you
The Earth's surface is _____ water.
50 %
71 %
97 %
Answer:
71%
Explanation:
Which ones are elements, compounds I’ll give brainliest.
Please help me this is my science final
Answer:
1.Winter
2.Autmn
3.Summer
4.Spring
I hope this helps!
What do all volcanos emit?
Answer:
By far the most abundant volcanic gas is water vapor, which is harmless. However, significant amounts of carbon dioxide, sulfur dioxide, hydrogen sulfide and hydrogen halides can also be emitted from volcanoes.
Which of the following characteristics is NOT used to classify organisms into groups?
a.
nucleus or no nucleus
c.
color or no color
b.
autotroph or heterotroph
d.
unicellular or multicellular
Answer:
b
Explanation:
Hydrogen bonds are in the family of Van der Waals forces. They are weaker than ionic and covalent bonds but they cause interesting changes with different chemicals.
What is one of the changes that hydrogen bonds are responsible for?
A. Cause DNA has the double helix shape.
B. Causes salts quickly dissolve in water.
C. Cause sugar looks like a crystal.
D. Cause liquid H2O to have a larger volume than frozen (solid) H2O
Answer:
The answer is B. Van der Waals forces are weaker than ionic and covalent bonds.
Explanation:
In general, if we arrange these molecular forces from the strongest to weakest, it would be like this:
Covalent bonds > Ionic bonds > Hydrogen bonds > Dipole-Dipole Interactions > Van der Waals forces
Covalent bonds are known to have the strongest and most stable bonds since they go deep and into the inter-molecular state. A diamond is an example of a compound with this characteristic bond.
Ionic bonds are the next strongest molecular bond following covalent bonds. This is due to the protons and electrons causing an electro-static force which results to the strong bonds. An example would be Sodium Chloride (NaCl), which when separated is Na⁺ and Cl⁻.
Van der Waals forces, also known as Dispersion forces, are the weakest type of molecular bonds. They are only formed through residual molecular attractions when molecules pass by each other. It doesn't even last long due to the uneven electron dispersion. It can be made stronger by adding more electrons in the molecule. This kind of molecular bonds appear in non-polar molecules such as carbon dioxide.
HOPE THIS HELPS!!!!!!!!!!!!!!
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The change that Hydrogen Bonds are most likely responsible for would be:
B). Causes salts to quickly dissolve in water.
As per the details provided, the hydrogen bonds are classified into the category of Van der Waals forces and the primary reason behind this has been that it leads salt to solvate immediately in the water. Amongst all the bonds, covalent bonds are characterized as the toughest while ionic bonds and hydrogen bonds are followed by it in terms of strength.The reason for which hydrogen bonds cause the change of allowing salts to dissolve immediately is that it illustrates a weaker strength of molecules due to its formation with residual uneven construction.Thus, option B is the correct answer.
Learn more about 'Covalent Bonds' here:
brainly.com/question/10777799
D. The ¬_____________________ converts food into energy. It is found in both plant cells and animal cells.
Answer:
I believe it’s the mitochondria
Explanation:
Answer:
Mitochondria
Explanation:
Ik bc i have the vocab for that question
WHAT TWO PLANT CELLS DONT PRODUCE PROTINES?!?!?!?!?
How are clouds formed? Simple answer please!
Answer:
Clouds form when the invisible water vapor in the air condenses into visible water droplets or ice crystals. For this to happen, the parcel of air must be saturated, i.e. unable to hold all the water it contains in vapor form, so it starts to condense into a liquid or solid form.
Explanation:
MARK ME BRAINLIEST!!!!!!!! THANKS BESTFRIENNNNNDDDDD!!!!!!!!
Answer:
Clouds form when the invisible water vapor in the air condenses into visible water droplets or ice crystals. For this to happen, the parcel of air must be saturated, i.e. unable to hold all the water it contains in vapor form, so it starts to condense into a liquid or solid form.
Explanation:
I HOPE THIS HELPS*--- *meow*
A sample of pure radioactive isotope is left to decay. After 40.0 days, the 1 point
sample is placed in a mass spectrometer, and it is determined that only
25% of the original isotope remains. How long is the half-life?
Answer:
6 months and 1 day
Explanation:
A vector is a quantity with magnitude and ____
Answer:
direction
Explanation:
A P E X
how to calculate the mass of fraction of all elements in calcium carbonate
(CaCO3)
Answer:
I have made it in above figure hope it helps
Many human activities result in carbon dioxide emissions.
Our carbon footprint is a measure of how much carbon dioxide we each cause to be produced.
(a) Why should we be concerned about our carbon footprint?
(b) Most power stations in the UK burn coal.
Coal was formed from tree-like plants over millions of years.
Suggest why burning wood instead of coal would help to reduce our carbon footprint.
Answer:
: the average human-driven CO2 emissions per year climbed 1.4%
every household makes about 7 tons worth of Co2
A C02 footprints are produced at such high rates and hurts plants and the environment
B coal is a very inexpensive and efficient way to generate electricity. Since its a large quantity of them which still produces alot co2 unlike wood, burning wood doesn't produce as much but it's much harder to ignite and get to last because it takes coal almost 100 degrees and wood takes about 700 degrees
Need a little help with science please
Answer:
I'm pretty sure its liver and pancreas
Explanation:
the pancreas delivers the digestive juice to the small intestine through small tubes, your liver makes the digestive juices called the bile that helps digest fats and some vitamins
Answer:
the answer is liver and pancreas
PLZ HELP!!!!!asapnow
Answer:
Friction of wind against the ocean surface
jupiter is much more larger than earth , would gravity be weaker or stronger here?
Answer:
stronger
Explanation:
there is more gravity on Jupiter since it is bigger than earth