Answer:
162.7miles/hr
Explanation:
Given parameters:
Distance covered by the train = 813.5miles
Time taken = 5hours
Unknown:
Speed of the train = ?
Solution:
Speed is a physical quantity.
It is mathematically expressed as;
Speed = [tex]\frac{distance}{time}[/tex]
So, input parameters and solve;
Speed = [tex]\frac{813.5}{5}[/tex] = 162.7miles/hr
When calculating percent error, the accepted value is in the denominator
True or false
Answer:
True
Explanation:
what do waves carry from place to place
Answer:
Waves carry energy from place to place.
Explanation:
Some waves are used for mainly communication and phone signals. They help people get internet in the middle of nowhere if you are near an energy wave.
A student submits the following work on the mass number, but he has made a few mistakes. Select the sentences that are incorrect.
Calculating the mass number for an atom requires that we know the atomic number and the number of protons in the atom’s nucleus. The mass number then gives us the average weight of atoms of a given element. Specifically, these units are calibrated by setting the mass number for carbon-12 as 12 atomic mass units. Neutrons and protons have the same masses. However, as long as the number of protons equals the number of neutrons, the values balance out and we always obtain a whole number for the mass number.
Answer
Calculating the mass number for an atom requires that we know the atomic number and the number of protons in the atom’s nucleus. The mass number then gives us the average weight of atoms of a given element. However, as long as the number of protons equals the number of neutrons, the values balance out and we always obtain a whole number for the mass number.
Explanation:
those 3
Given: (52.6 cm)(1.214 cm)
What is the product expressed to the correct number of significant figures?
1.
64 cm2
2.
63.9 cm2
3.
63.86 cm2
4.
63.8564 cm2
Answer:
2.
63.9 cm2
Explanation:
All non-zero digits are consider significant figures like 1, 2, 3, 4, 5, 6, 7, 8, 9.
Leading zeros are not consider as a significant figures. e.g. 0.06 in this number only one significant figure present which is 6.
Zero between the non zero digits are consider significant like 108 consist of three significant figures.
The zeros at the right side e.g 240000 are also significant. There are six significant figures are present.
When we add or subtract the values the number of significant figures after decimal in result must be equal to the given measurement having less number of decimal places. For example,
The difference between 7.69 and 4.0.
7.69 - 4.0 = 3.7
When we multiply or divide the values the number of significant figures must be equal to the less number of significant figures in given value.
For example in given q:
52.6 cm × 1.214 cm = 63.9 cm²
Is the study of the living plants and animals in the ocean
Answer:
marine biologist
Explanation:
marine biologist
Answer:
marine biologist a scientist who studies creatures that live in ocean water, from bacteria and shellfish to kelp and whales. mean One of several measures of the “average size” of a data set. .organism Any living thing, from elephants and plants to bacteria and other types of single-celled life.
Which of the following is the proper scientific notation for the number
18,200?
O A. .182 x 105
B. 1.82 x 104
O c. 18200 x 100
O D. 182 x 102
The Answer fam is......... 1.82 × 10^4, Hence It's B)
List the different sizes of sediment.
Answer:
Smallest to Largest:
Clay is smaller then 1/125 mm
Silt is 1/256- 1/16 mm
Sand is 1/16-2 mm
Pebble is 2-64 mm
Cobble is 64-256 mm
Boulder is greater then 256 mm
Explanation:
Element X has two naturally occurring isotopes. The isotope with mass 62.93 amu has a
relative abundance of 69.2%. The isotope with mass 64.93 amu has a relative
abundance of 30.8%. Calculate the average atomic mass of Element X. What is the
identity of Element X?
Consider the following unbalanced equation.
Ca(OH)2 + (NH2)2SO4 → CaSO4 + NH3 + H2O
Help for 70 points please explain why too.
Answer:
1 Ca(OH)2 + 1 (NH4)2SO4 ---> 1 CaSO4 + 2 NH3 + 2 H2O
Explanation:
The photo I attached should make more sense as an explanation.
When balancing equations, the first and most important step is to count the # of each type of element on each side.
In this problem there are 5: Ca, O, H, N, and S.
Once you do that you can begin balancing.
Here is the initial tally for the elements in this problem:
On the left.....
Ca - 1
N - 2
S - 1
O - 6
H - 10
On the right.....
Ca - 1
N - 1
S - 1
O - 5
H - 5
Looking at these values, we can see N, O, and H all need adjusting the right side. You should never start balancing with O or H unless they are the only elements that need adjusting. They usually balance out with the rest of your work or with water in the end.
So given all of that, you should start balancing with N on the right. Giving NH3 a coefficient of 2 will change the number of Nitrogen atoms on the right to 2. Be careful though! It will also change the number of Hydrogen atoms from 5 to 8 (because (2*3) =6 and 6+2 =8).
Let's tally our numbers again.
On the left..... (these should be unchanged)
Ca - 1
N - 2
S - 1
O - 6
H - 10
On the right.....
Ca - 1
N - 2
S - 1
O - 5
H - 8
Okay, now we see only O and H need adjusting on the right. Luckily there is H2O so we can do that without impacting the number of other atoms.
Give H2O a coefficient of 2 and count the number of atoms on the right again.
On the right.....
Ca - 1
N - 2
S - 1
O - 6 (because 4 from CaSO4 plus 2 from 2H2O = 6)
H - 10 (6 from NH3 plus 4 from 2H2O = 10)
Do these numbers match what you have on the the left side of the equation? Yes! It is balanced so you do not need to adjust anymore. Your coefficients in the answer will be 1-1-1-2-2.
Michelle learns in science class that simple machines such as an inclined plane can change the amount of force needed to lift heavy objects. She decides to test this with an experiment.
Michelle chooses a 10 kg weight. She sets up a ramp made of smooth metal that makes an angle θ with the floor. She attaches a spring scale to the weight and the top of the ramp in order to hold the weight in place. She records the force from the spring scale, then changes θ and records it again. She repeats this several times.
In this experiment, what is the dependent variable?
A.
the mass of the weight
B.
the angle θ between the ramp and the ground
C.
the amount of force on the spring scale
D.
the material the ramp is made of
Be fast please
A penny is 2.5 g. How many kilograms does a penny weigh?
Answer:
The penny now weighs 0.0025kg
Hope this helps please give me brainliest!
God bless!
Determine the amount of energy (heat) in Joules and Kcal required to raise the temperature 0f 98.5 grams water from 37.0 0C to 75.0 0C.
Answer:
15660.712J
Explanation:
Q = m × c × del T
Q(energy) = ?
m (mass) = 98.5g
c = 4.184J
del T = 75-37 = 38 °C
Q = 98.5 × 4.184 × 38
Q = 15660.712 J
The valence electrons are those found in the highest energy ____ and ___ orbitals
^Please help ASAP I’ll mark you as brainlister FILL in the blank
The outmost free electron which is present in the outer shell is called valency. The number of elements joining together to form the compound also depends on the valency.
Each electron has revolved around the nucleus and that path is considered as orbit. The orbit is as follows:-
SPDFThe free electrons are usually lie in the outmost shell.
Hence according to the question, the correct option is S and P orbit.
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A student drops a 95g object into a graduated cylindor that has 30ml of water in it. After the object is added to the cylinder the water level reads 63ml. What is the density of the object?
Answer:
The answer is 2.88 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\ [/tex]
From the question
mass = 95g
volume = final volume of water - initial volume of water
volume = 63 - 30 = 33 mL
We have
[tex]density = \frac{95}{33} \\ = 2.87878787...[/tex]
We have the final answer as
2.88 g/mLHope this helps you
what is the average distance between the sun and earth in summer and winter
Answer:
93,000,000 miles (8.5 light minutes)
Explanation:
In the northern hemisphere's winter, the earth is slightly closer to the sun than in the southern hemisphere's winter season
Refer to your periodic table:
Which of the following has the smallest atomic radius?
Bromine
Astatine
Iodine
Fluorine
iondine
Explanation:
bromine has 185pm, astatine haa 200, iondine has 140 and lastly fluorine has 147. so iondine has the smallest atomic radius
Part 1 Designing an Investigation
Melinda was cooking a pizza and removed the pizza from the
oven, which was set to 400 degrees Fahrenheit. She wanted to
cool down the pizza as quickly as possible to eat it. In her house,
she had a freezer (set to 0 degrees Fahrenheit), a refrigerator
(set to 40 degrees Fahrenheit), and the countertop (which is at
the temperature of the room, 78 degrees Fahrenheit).
1. Design an experiment that will let Melinda study which of
the three options, the refrigerator, the freezer, or the room, will let the pizza cool down the fastest.
Experimental Question (How does (IV) the heat
affect the pizza to cool down
DV)
Independent Variable
Dependent Variable
Experiment Plan
Answer:
The experimental plan is to measure the values of the dependent variable, which is the temperature of the pizza after it is cooled in each of the heat (temperature) environments, which is the dependent variable, for a given equal period of time, which is the control
Explanation:
The given parameters are;
The temperature of the pizza = 400°F
The temperature of the freezer = 0°F
The temperature of the refrigerator = 40°F
The temperature of the countertop = 78°F
Given that the independent variable = The heat to which the hot pizza is subjected
The dependent variable = The temperature to which the pizza cools down
The experiment plan includes;
1) Place the pizza which is at 400°F in each of the different heat environment, which are, the freezer, the fridge, and the counter top, for the same period of time and record the final temperature of the pizza
2) The option that gives the lowest final temperature within the same time frame is the option that will let the pizza cool down fastest.
Planets A and B are both the same size, but planet B has three times the mass of planet A. How does the weight of an object compare on the two planets?
Choose the correct answer.
The weight of an object is the same on both planets.
The weight of an object is three times larger on planet A.
The weight of an object is three times larger on planet B.
The weight of an object will depend on more factors than just the weight and size of the planet.
Answer:
The answer is d
Explanation:
Explain what happens if the nucleus, of an atom, becomes unstable.
Answer:The unstable nucleus of radioactive atoms emit radiation. When this occurs, a new atom and element are formed. This process is called radioactive decay. It continues until the forces in the unstable nucleus are balanced.
Explanation:
What is the correct order of increasing elec-
tronegativity?
1. Si, P, S, C, N, O, F
2. O, C, N, S, P, Si, F
3. F, Si, P, S, N, C, O
4. F, O, N, C, S, P, Si
Answer:
ceo que3
Explanation:
Solid substance A has a melting point of 100°C. Liquid substance B has a freezing point of 110°C. For each substance, identify its state of matter and describe the motion of its particles when the substance is at 115°C.
Answer:
both will be at liquid state. the particles will move rapidly in all directions and will collide with other particles in random motion
True or False: A Precipitate is a solid
that forms out of a liquid solution as a
result of a chemical reaction
Answer:
true because it undergoes a tranformation
Explanation:
Which statement about aldehydes and ketones is correct?
A) In aldehydes, the carbon is always joined to at least one hydrogen atom.
B)Every ketone molecular formula is unique.
C) Aldehydes are similar to ketones, but their carbonyl group is located in the middle of the carbon chain.
D) In ketones, the carbon of their carbonyl group is bonded with one other carbon.
Answer:
A) In aldehydes, the carbon is always joined to at least one hydrogen atom.
Explanation:
Aldehydes and Ketones are organic compounds.
The main difference between them is that aldehydes have the carbon atom attached to at least one hydrogen atom.
In ketones, the carbon is attached to another carbon.
The IUPAC names of alkanals usually end with -eFor alkanones usually end with -oneTo reiterate, the striking difference between the two families is that in alkanals, a hydrogen atom is directly attached to the carbonyl group while in alkanones, no hydrogen atoms is attached to the carbonyl group but two bulky alkyl groups.
How many grams are in 2.75 moles of Calcium
Answer:
110.21 g/mol
............................
Answer:
110.22 g in 2.75 moles of calcium
Explanation:
to convert moles to grams
moles (g/mol)
2.75 mol Ca (40.08 (atomic weight) g Ca/1 mol Ca)= 110.22
If an object increases in speed, it must be as a result of
o increasing friction.
o unbalanced forces.
O gravitational attraction.
O air resistance.
please hurry i’m taking a test
Answer:
a; increasing fraction
Explanation:
Can someone help me with number two pls
Answer:
The answer is G
Explanation:
this is because of what a element looks like on a periodic table
Answer:
F. 1 and 3
Elements are pure substance
5. Aidan is on a carnping trip with his family. As the temperature decreases
Aidan suggests building a campfire. Which of the following explains why
heat moves from the campfire to the people sitting around it? *
Answer:
Because heat flows from warmer objects to cooler objects
Explanation:
what chemical is C2H4O2
Answer:
C2H4O2 is Acetic acid.
Explanation:
Acetic acid is a colourless liquid organic compound with the chemical formula CH3COOH (also written as CH3CO2H or C2H4O2). It is in the department of a chemical compound known as Glycolaldehyde. It is the smallest possible molecule that contains both an aldehyde group and a hydroxyl group.
Explain what lattice energy is and how it affects the properties of ionic compounds. Describe the general properties of ionic compounds.
Answer:
The force of attraction between oppositely charged particles is directly proportional to the product of the charges on the two objects (q1 and q2) and inversely proportional to the square of the distance between the objects (r2).
The strength of the bond between the ions of opposite charge in an ionic compound therefore depends on the charges on the ions and the distance between the centers of the ions when they pack to form a crystal.
An estimate of the strength of the bonds in an ionic compound can be obtained by measuring the lattice energy of the compound, which is the energy given off when oppositely charged ions in the gas phase come together to form a solid.
Explanation:
The lattice energies of ionic compounds are relatively large. The lattice energy of NaCl, for example, is 787.3 kJ/mol, which is only slightly less than the energy given off when natural gas burns.
The bond between ions of opposite charge is strongest when the ions are small.
The ionic bond should also become stronger as the charge on the ions becomes larger.
Answer:
The force of attraction between oppositely charged particles is directly proportional to the product of the charges on the two objects (q1 and q2) and inversely proportional to the square of the distance between the objects (r2). The strength of the bond between the ions of the opposite charge in an ionic compound therefore depends on the charges on the ions and the distance between the centers of the ions when they pack to form a crystal. An estimate of the strength of the bonds in an ionic compound can be obtained by measuring the lattice energy of the compound, which is the energy given off when oppositely charged ions in the gas phase come together to form a solid.
Explanation:
Got it right on edge 2020
4. Calculate the energy (E) and wavelength (1) of a photon of light with a frequency of
6.165 x 1014 Hz.
PLEASE HELP!!
Answer: E= 4.085 x 10^-19 J ; Wavelength= 4.862 x 10^-7 m
Explanation:
Sorry for the messy work, but I hope this helps.
Remember:
Plancks constant (h)= 6.626x10^-34 Js
Speed of light (c) = 2.998 x 10^8 ms^-1
What I did:
I found the energy first with the given frequency. Don't forget to convert your units to s^-1! They are actually the same, you dont need to do math for that conversion, just a simple Hz to s^-1.
For the wavelength, I multiplied plancks constant (h) and speed of light (c) together. With that number I divided by the energy found which 4.085 x 10^-19J. Also, be sure to cross off the units because it can get very confusing.
The energy of the photon is 4.08 x 10⁻¹⁹ J
The wavelength of the photon is 2.58 x 10⁻⁶ m
The given parameters;
frequency of the photon, f = 6.165 x 10¹⁴ Hz
The energy of the photon is calculated as;
E = hf
where;
h is Planck's constant = 6.626 x 10⁻³⁴ Js
E = (6.626 x 10⁻³⁴)( 6.165 x 10¹⁴)
E = 4.08 x 10⁻¹⁹ J
The wavelength of the photon is calculated as;
v = fλ
where;
v is the speed of light = 3 x 10⁸ m/s
[tex]\lambda = \frac{v}{f} \\\\\lambda = \frac{3\times 10^8}{1.165\times 10^{14}} \\\\\lambda = 2.58 \times 10^{-6} \ m[/tex]
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