Answer: D.
Explanation:
Moji listed the solids in order of hardness as graphite < chalk < quartz. because his peer group suggested some experimental errors that may have caused this to happen. The experimental error most likely led Moji to the conclusion that Moji could have chosen hardness tests that were not reliable. Therefore the correct option is D.
What is the matter?Anything which has mass and occupies space is known as matter, mainly there are four states of matter solid liquid gases, and plasma.
These different states of matter have different characteristics according to which they vary their volume and shape.
There are various tests to judge the mechanical hardness of any solid material such as the Rockwell hardness test, Brinell's hardness test,Vicker's diamond hardness test, and Knoop's hardness test which is also known as microhardness test
The experimental error most likely led Moji to the conclusion that Moji could have chosen hardness tests that were not reliable. Therefore the correct option is D.
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Does anyone know how to do this pleaseeeee
Answer:
See the answer below.
Explanation:
The latent heat of fusion is defined as the amount of energy needed to make a phase change from solid to liquid. And it can be calculated by means of the following expression:
[tex]Q_{fusion}=m*Dh[/tex]
where:
Qfusion = Heat Energy [J]
m = mass = 0.65 [kg]
Dh = latent heat fusion = 330000[J/kg]
[tex]Q_{fusion}=0.65*330000\\Q_{fusion}=214500[J][/tex]
2)
We know that energy can be calculated from power, where power is defined as the relationship between energy over time.
[tex]P=E/t[/tex]
where:
P = power = 60 [w]
E = energy [J]
t = time = 5 [min] = 300 [s]
[tex]E=P*t\\E=50*300\\E=15000[J][/tex]
The mass change due to the process is equal to:
[tex]m=282-274\\m=8[g]=0.008[kg][/tex]
Now using the following equation for the latent heat of Fusion, we can calculate this value:
[tex]Q=m*Dh\\Dh =Q/m\\Dh=15000/0.008\\Dh=1875000[J/kg][/tex]
Stephanie is in volleyball practices and she notices something interesting about the
effect that spiking the ball has on her hand. She notices that the harder she hits the
ball, the more that her hand hurts afterward. Which Newton's Law explains why this
happens?
The Newton's law that explains the reason for the pain experienced by Stephanie when she spikes the ball is Newton's third law of motion.
Newton's third law of motion, states that, action and reaction are equal and opposite.
The force exerted on the ball when Stephanie spikes is equal to the reaction the ball exerts back on Stephanie. As the force Stephanie applied increases, the reaction she receive from the ball increases as well and the more pain she will feel.
Thus, we can conclude that, the Newton's law that explains the reason for the pain experienced by Stephanie when she spikes the ball is Newton's third law of motion.
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What happens to the energy when the material is changed?
Answer: When a material is heated or cooled, two changes may happen to the particles within the material: Chemical bonds between the particles may form, break or stretch. There is a change in the chemical potential store of energy in the material. The material will heat up or cool down as the particles within it gain or lose speed.
Explanation:
three advantages of simple machines.please tell fast
Answer:
they can help make clothing, they are useful for human like work, they are better than hand making
7. The S.l. unit for force is
A. kg
C. m/s
B. m/s2
D. N
Which statement about this figure is false
A. Line E represents a fault line.
B. Layer C is the youngest layer.
C. d,ike K is older than layer I.
D. The fault occurred after layer F formed.
The statement about the figure that is false is that d,ike K is older than layer I. That is option C.
What is cross-cutting relationships in geology?Cross-cutting relationships is a principle that when a body pass through different layers in geology, it is usually younger than all the layers it passed through.
That is to say that, d,ike K is younger than layer I, D and B which it passed through.
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Answer:
If it's not C then it HAS to be B.
Explanation:
By deductive reasoning.
b. Find the velocity of a rider on the ride.
Given:
a =
r =
Unknown:
V =?
Equation:
a = v^2/r
Or
v^2 = a*r
Solution
D
Explanation:
Mutiply and alagrab to subterc
A box on the ground is being pulled from the left and right by string. The box is accelerating to the left. What five forces are being used?
Answer:
push and pull,kinetic energy,force,and motion. I hope this helped if I get you this question wrong I deerly aploizge.
Determine the mass of a boat that is propelled forward by a force of 1250N at an acceleration of 3 m/s2.
Answer:
416.6 KG
Explanation:
Due to the mass being missing from the equation you divide the force by the acceleration
Which example of heat transfer is due mainly to convection?
Imagine you are an astronomer who recently discovered a new planet orbiting a distant star. Which set of characteristics would you use to classify this planet as an inner or terrestrial planet? Check all that apply.
-dense and solid
-very large
-thick atmosphere containing hydrogen and helium
-lacking a solid surface
-located near a star
Answer:
The right characteristics to be used for the classification include:
-dense and solid
-very large
-located near a star
Explanation:
The above listed characteristics are part of the characteristics used in classifying a planet as a habitable planet or non-habitable one. When a planet is closer to a star which revolves around it, this helps in supplying the needed light to it.
Answer:
dense and solid
located near a star
Explanation:
A boy and a girl are balanced on a massless seesaw. The boy has a mass of 75 kg and the girl's mass is 50 kg. If the boy sits 2.0 m from the pivot point on one side of the seesaw, where must the girl sit on the other side?
Answer:
The girl must sit 5 m on the other side of the seesaw.
Explanation:
Given;
mass of the boy, = 75 kg
mass of the girl, = 50 kg
distance of the boy from the pivot, = 2 m
let the distance of the girl from the pivot = d
<-------------2m-------------><-------------d-------------->
-----------------------------------------------------------------------------------
↓ Δ ↓
75 50
Apply the principle of moment, about the pivot;
clockwise moment = anticlockwise moment
75 x 2 = 50 x d
150 = 50d
d = 150 / 50
d = 3 m
The distance of the girl from the pivot is 3 m.
Therefore, the girl must sit ( 2m + 3m ) on the other side of the seesaw.
If a certain test follows a normal curve, most of the scores will fall
A. at the top end
B. at the bottom end
C. all over the place
D. in the middle
Please select the best answer from the choices provided
Ο Α
OB
С
OD
Answer:
im pretty sure its d
Explanation:
A motorcycle engine provides 473.3 N of force for 11.9 seconds. If the rider and the cycle have a mass of 2,068.3 kg, determine the change in velocity.
Answer:
After 11.9 seconds, the velocity will increase by approximately 2.7 m/s
Explanation:
Ignoring friction, we can simply say that the speed will increase by
11.9s × 473.3N / 2068.3kg
Which can be expressed as:
11.9s × 473.3kg·m/s² ÷ 2068kg
= (11.9 × 473.3 ÷ 2048.3) (kg·m/s² × s ÷ kg)
≈ 2.7 m/s
The current flowing through the heating element when a toaster is plugged into a 230V mains supply, if the element has a resistance of 265Ω.
Answer:
The current flowing the heating element is 0.868 amperes.
Explanation:
Ohm's law states that voltage is directly proportional to current. In other, words, we say that:
[tex]V \propto R[/tex]
[tex]V = i\cdot R[/tex] (1)
Where:
[tex]V[/tex] - Voltage, measured in volts.
[tex]i[/tex] - Current, measured in amperes.
[tex]R[/tex] - Resistance, measured in ohms.
If we know that [tex]V = 230\,V[/tex] and [tex]R = 265\,\Omega[/tex], then the current that flows through the heating element is:
[tex]i = \frac{V}{R}[/tex]
[tex]i = \frac{230\,V}{265\,\Omega }[/tex]
[tex]i = 0.868\,A[/tex]
The current flowing the heating element is 0.868 amperes.
Explained and elaborate further the function of assessing responsiveness
Find the centripetal force needed to keep an 60.0 kg rider traveling in a circle in the ride.
Given:
m=
V = (from part a)
R =
Unknown:
F=?
Equation:
F= m (y^2) / r
Explanation:
Given that,
Mass of the rider, m = 60 kg
Let the radius of the circle, r = 30 cm = 0.3 m
Let the velocity, v = 20 m/s
We need to find the centripetal force needed to keep the rider in a circular path. It can be given by :
[tex]F=\dfrac{mv^2}{r}\\\\F=\dfrac{60\times (20)^2}{0.3}\\\\F=80000\\\\\text{or}\\\\F=8\times 10^4\ N[/tex]
So, the required force is [tex]8\times 10^4\ N[/tex].
Please Help Me!!!.......
Answer:
D
Explanation:
Water has a high surface tension because the water molecules on the surface are pulled together by strong hydrogen bonds. That means a drop of water will "want" to have the smallest possible surface area.
You are researching a fungus that can kill banana plants. Which source is
likely to have the least reliable information?
A. An article in a popular science magazine
B. A press release about research on the fungus posted on the
website of a university
C. A posting about the fungus on a social media site
D. A report about the fungus on a nightly news show
Answer:
B
Explanation:
what could i say except ur welcome
Please I need help with this question (see image).
Show workings where necessary.
Answer:
Solution:
i) Heat supplied by heater = Heat gained by water = m * c*theta = 0.12Kg * 4200 * 10 = 5040Joules in 2 minutes.
ii) Power = Energy/time = 5040J/(2 * 60seconds) = 5040J/120seconds = 42Watts.
(iii) Heat supplied to the 70g of water = m * c * theta = 0.07Kg * 4200 * 9K = 2646J
(iv) Heat supplied by heater = Heat gained by 70g of water + Heat supplied to the metal vessel.
But,from our calculations above,
Heat supplied by heater = 5040J ......and
Heat supplied to the 70g of water = 2646J
.: substituting the values,we have that :
5040J = 2646J + Heat supplied to the metal vessel.
5040J - 2646J = Heat supplied to the metal vessel.
.: Heat supplied to the metal vessel = 2394J.
(v) Heat gained by metal vessel = Heat capacity of the vessel * theta.
2394J = Heat capacity of the vessel * 9K
.: Heat capacity of the vessel = 2394/9 = 266(Joule per Kelvin)
(vi) Using the formula:
Heat Capacity = mass * specific heat capacity
.: Specific heat capacity = Heat Capacity/mass = 266/0.55 = 484(Joules per Kilogram per Kelvin)
Explanation:
________❤️ hope it helps you ❤️__________what substance is used by plants as a source of food
Answer:
dart
Explanation:
dart and sun and water so that the plant be okay
Which is a possible result of rising ocean temperatures caused by global warming?
formation of dust bowls
increase in strength of hurricanes
rapid evaporation of water in soil
decrease in population due to health threats
Answer:
Increase in strength of hurricanes
Explanation:
A possible result of rising ocean temperatures caused by global warming is an increase in the strength of hurricanes, which is the second option. As the ocean temperatures increase, more energy is available to fuel hurricanes, making them stronger and potentially more destructive.
What is global warming?Global warming is causing the earth's climate to change, which is having a significant impact on the world's oceans. As the temperature of the oceans increases, a variety of effects can occur. One of the most well-documented impacts is the increase in the strength of hurricanes. Hurricanes form over warm ocean waters, and as the water temperature rises, it provides more energy to the storm, making it more powerful.
Hence, a possible result of rising ocean temperatures caused by global warming is an increase in the strength of hurricanes, which is the second option.
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In which stage of sleep are you likely to experience hypnagogic
sensations of falling asleep
NREM-1 got this off a website
A big kid pushes a little kid and the little kid falls backward. The big kid remains relatively stationary. What best explains this
Answer:
Becase he pushed the little kid not himself
Explanation:
The Big Bang Theory was supported by the discovery of the
red shift in electromagnetic spectrum
gravitational force between planets
temperature of the universe
galaxies in the universe
What will most likely happen if a sound wave moves from the air through a solid?
It will increase in wavelength.
It will decrease in speed.
It will increase in speed.
It will decrease in wavelength.
1. what is the average speed after two seconds?
2. after three seconds?
3. after 5 seconds?
4. what is the average speed between two and four minutes?
5. what is the average speed between four and five minutes?
Answer:
1. 75 speed, 2. 90 second = 1hr. 30 second. 3. 125 = 1hr 60 seconds 4.
How does energy travel? Where is the initial source of energy in our solar system? What is the process that gives off energy from the sun called?
Answer:
How does energy travel?
One way the energy can travel is through radiation. An object can radiate energy in the form of electromagnetic waves, for example when a strong light is turned on and you can feel some heat coming from it, or when you walk under the sunlight and you can feel the heat in your skin.
Where is the initial source of energy in our solar system?
In the solar system, the source of energy comes from the Sun, and the sun irradiates that energy to all the nearby objects.
What is the process that gives off energy from the sun called?
The process is called radiation, this is all the energy that comes from the sun in the form of different electromagnetic waves (light in the visible range, UV rays, etc...)
a tree is blank relative to earth a tree is blank relative to the sun
hmmmmmmmmmmmmmmmmm ask someone else sorry if im not helping
How fast is a 85 kg football player moving if they have a momentum of 125 kg*m/s?
Answer:
v = 1.5 m/s
Explanation:
m = 85 kg
p = 125 kg m/s
v = ?
p = m v
125 kg m/s = (85 kg) (v)
v = (125 kg m/s) / (85 kg)
v = 1.47 m/s