The time it would take a 2500 W electric kettle to boil away 1.5 Kg of water is 2400 seconds
How to calculate the timeUse the formula:
Power × time = mass × specific heat
Given mass = 1. 5kg
Specific latent heat of vaporization = 4000000 J/ Kg
Power = 2500 W
Substitute the values into the formula
Power × time = mass × specific heat
2500 × time = 1. 5 × 4000000
Make 'time' the subject
time = 1. 5 × 4000000 ÷ 2500 = 6000000 ÷ 2500 = 2400 seconds
Therefore, the time it would take a 2500 W electric kettle to boil away 1.5 Kg of water is 2400 seconds.
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please help
a piece of wood of mass 40g and uniform cross-sectional area of 2cm^2 floats upright in water. calculate the length of the immersed part of the wood
The length of the immersed part of the wood is 0.2m.
What is density?The density is the ratio of the mass and the volume of the object. It is denoted by ρ.
ρ = mass/Volume = m/V
Volume = Area of cross-section A x height h
Given is a piece of wood of mass 40g =0.04kg and uniform cross-sectional area A= 2cm² =2x10⁻⁴ m² floats upright in water.
The density of water ,ρ = 1000 kg/m³
The density related to length of part immersed is
1000 = 0.04/ (2x10⁻⁴ x h)
h = 0.2m
Thus, the length of the immersed part of the wood is 0.2m.
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L 6.3.2 Test (CST): Applications of Waves Question 5 of 10 Which event provides evidence that matter can reflect waves? O A. An audience member covers her ears during a loud concert. B. A laser beam bounces off a series of mirrors. C. A performer makes shadow puppets on a wall. D. The light from a fireworks show is seen miles away.
An audience member covers her ears during a loud concert shows evidence that matter can reflect waves.
Which event provides evidence that matter can reflect waves?An audience member covers her ears during a loud concert is an event that provides evidence that matter can reflect waves because a sound is heard again and again due to the reflection of waves. This repetition of sound is due to the property of reflection of sound waves.
So we can conclude that an audience member covers her ears during a loud concert shows evidence that matter can reflect waves.
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Answer:
A laser beam bounces off a series of mirrors
Explanation:
Six students each make an electromagnet for an investigation. Each student wraps copper wire around a nail and attaches each end of the wire to a 9-volt battery. The students use their electromagnets to pick up paper clips. The table shows the number of paper clips each student picks up with their electromagnet.
a) Write one question about how the electromagnets were made that the students could answer that would help explain the differences in the numbers of paper clips picked up by the electromagnets. Explain your reasoning.
b) Identify one factor, other than how the electromagnets were made, that would affect the number of paper clips picked up by the electromagnet. Explain your reasoning.
The question on how electromagnets are produced that students may answer to help explain the disparities in the quantity of paper clips taken up by the electromagnets "What is the strength of electromagnet”
What is static electricity?The imbalance of electric charges within or on the surface of a substance, or between materials, is known as static electricity.
Static electricity is generated by Van de Graaff generators. Static does not include acceleration, implying that it is stationary, which pertains to the formation of electric charges.
a)The question on how electromagnets are produced that students may answer to help explain the disparities in the quantity of paper clips taken up by the electromagnets "What is the strength of electromagnet”
b)The one factor, other than how the electromagnets were manufactured, that influences the quantity of paper clips the electromagnet picks up will be electrostatics.
Hence,the whole activity is about the electromagnets.
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it is seen that in a balloon filled with air,if we press one side of the balloon the other side bulges out.why is it so???
When we apply pressure on the one side of balloon the other side bulges out due to the movement of gas to other side.
What happen when we press one side of the balloon?If we press one side of the balloon, the other side bulges out because the gas that present on one side moves to the other side where there is no pressure. The body of balloon is elastic so when we apply pressure the other side bulges out.
So we can conclude that when we apply pressure on the one side of balloon the other side bulges out due to the movement of gas to other side.
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Planetary Nebula/White Dwarf Stars - Little Ghost Nebula. Some red giant stars develop into planetary nebulas as their cores continue to contract, to increase in temperature, and to burn and vent the remaining gases into interstellar space. Eventually, the core collapses to the point where it is hot enough to ionize the vented gases, forming a relatively short-lived (~10,000-20,000 years) planetary nebula. The remaining core collapses into a white dwarf star. The vented materials from the planetary nebula play an important role in enriching the universe in elements with atomic weights less than 26 (forming the basis for carbon-based life like ourselves!). Which type of star will form a planetary nebula
Smaller stars, like our sun, die by ejecting their outer layers of gas into space, resulting in the formation of a planetary nebula.
How planetary nebula formed?A planetary nebula is formed when a red giant ejects its outer atmosphere. A white dwarf is the carbon core of a star that has lost its photosphere.
This results in a one-of-a-kind and breathtaking creation known as a planetary nebula.
Smaller stars, like our sun, die by ejecting their outer layers of gas into space over a 10,000-year period, leaving behind the star's heated core.
Radiation from the white dwarf causes the gas to shine, resulting in a one-of-a-kind and stunning creation known as a planetary nebula.
The carbon core of a red giant that has evacuated its photosphere as a planetary nebula is a white dwarf.
Hence, Smaller stars, like our sun, die by ejecting their outer layers of gas into space type of star will form a planetary nebula
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Pls help me l will make it brainlest
Answer:
0.04 °C⁻¹
Explanation:
First, we need to calculate linear expansivity, then after finding that value, we can move on to finding the area expansivity.
=============================================================
Finding Linear Expansivity :
⇒ α = Final length - Original length / (Original length × ΔT)
⇒ α = 9 - 4 / (4 × 70 - 20)
⇒ α = 5 / 5 × 50
⇒ α = 0.02
============================================================
Finding Area Expansivity :
⇒ Area Expansivity = 2 × Linear Expansivity
⇒ β = 2 × α
⇒ β = 2 × 0.02
⇒ β = 0.04 °C⁻¹
Calculate the value of the area expansion of a steel rod of lenght 4cm at 20°c after heating attains another length of 9cm at 70°c.
Area = 0.02
Area Expansity = [tex]0.0 {4}^{ - 1} [/tex]
True or false: Scientific models are always built to scale, and are fully functional representations of the product they are testing.
Answer:
False
Explanation:
Scientific models are not always built to scale and may not be fully accurate
Diverse crops can become vulnerable to pests, disease, and climate change. Which part of this statement is false?
The statement 'diverse crops can become vulnerable to pests, disease, and climate change' is considered false regarding this last point (climate change).
What is adaptation?Adaptation is an evolutionary process where a species fits certain environmental conditions.
Plant species are intrinsically vulnerable to climate change because they are adapted to certain climate (temperature) conditions.
In conclusion, the statement 'diverse crops can become vulnerable to pests, disease, and climate change' is considered false regarding this last point (climate change).
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17.
_______ energy is energy that is stored or waiting to be used.
Mechanical
Kinetic
Electrical
Potential
What can you infer about the changes in the environment over time at the mystery fossil dig site? Record your inferences in the spaces provided.
Describe the environment in Egypt before the mystery fossil organism emerged.
the fossil informed us about the climatic and geographical changes that occurs in the environment over time.
What the mystery fossil dig site informed us about environment?We can infer about the climate and geographical changes in the environment over time at the mystery fossil dig site because the fossil provides us information about the climatic condition as well as the geography of land when this fossil organism were alive.
So we can conclude that the fossil informed us about the climatic and geographical changes that occurs in the environment over time.
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On a hot day, the deck of a small ship reaches a temperature of 48
17.0°C seawater on the deck to cool it down. During the cooling, 3,710,000 J are transferred to the
seawater from the deck. Assume no energy or mass is lost from the system. Use c = 3,930 J/kg°C for
seawater.
Calculate the final temperature of the seawater-deck system.
Write your answer rounding to the nearest tenth.
The final temperature of the seawater-deck system is 990°C.
What is heat?The increment in temperature adds up the thermal energy into the object. This energy is Heat energy.
The deck of a small ship reaches a temperature Ti= 48.17°C seawater on the deck to cool it down. During the cooling, heat Q =3,710,000 J are transferred to the seawater from the deck. Specific heat of seawater= 3,930 J/kg°C.
Suppose for 1 kg of sea water, the heat transferred from the system is given by
3,710,000 = 1 x 3,930 x (T - 48.17)
T = 990°C to the nearest tenth.
The final temperature of the seawater-deck system is 990°C.
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Three resistors of 100 W, 3900 W, and 1000 W are connected in series across a 200-V battery. What is the voltage drop across the resistor of value 1000 W?
Answer:
40 V
Explanation:
I will assume that the resistors are
100 and 3900 and 1000 OHMS <=====(NOT W)
In series , the resistances add together 100 + 3900 + 1000 = 5000 ohms total
V = IR
I = V / R so the total current will be 200 v / 5000 ohms = .04 amps
this is the current through all of the resistors
so for the 1000 ohm resistor V = IR .04 (1000) = 40 V
You suspect that the power supply in your desktop pc is failing. you want to use a multimeter to test the power supply. which multimeter setting should you use
The multimeter setting should you use is between 11-12 volts. If the voltage is too high or too low, the power supply must be changed.
What is a multimeter?An instrument made to measure resistance, voltage, and electric current, often across a range of values.
You think your desktop computer's power supply is malfunctioning. To test the power supply, you should use a multimeter.
Between 11 and 12 volts should be seen on the multimeter. The power supply is failing and has to be replaced if it's too high or too low.
Hence, the multimeter setting should you use is between 11-12 volts.
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A boy is trying to roll a bowling ball up a hill, as shown in the image below. If
friction is ignored, what is the minimum initial velocity that the ball must have
for it to reach the top of the hill? (Recall that g = 9.8 m/s²)
22.5 m
O A. 28 m/s
O B. 7 m/s
OC. 14 m/s
OD. 21 m/s
The minimum initial velocity that the ball must have for it to reach the top of the hill is 21 m/s. The correct option is D.
What is mechanical energy?The mechanical energy is the sum of kinetic energy and the potential energy of an object at any instant of time.
M.E = KE +PE
A boy is trying to roll a bowling ball up a hill. The friction is ignored. The ball must have to reach the top of the hill with a velocity. The acceleration due to gravity, g = 9.8 m/s²
The conservation of energy principle states that total mechanical energy remains conserved in all situations where there is no external force acting on the system.
M.E bottom of hill = M.E on top of hill
Kinetic energy + Potential energy = Kinetic energy + Potential energy
1/2 mu² + 0 = 0 + mgh
At the top of hill, the velocity will become zero. So, final kinetic energy is zero.
Substituting the values, we have
1/2 x u² = 9.8 x 22.5
u = sqrt [2 x9.8 x 22.5 ]
u= 21 m/s
Thus, the minimum initial velocity that the ball must have for it to reach the top of the hill is 21 m/s.
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What happens to the cost of goods when inflation increases?
OA. The cost of goods decreases.
B. The cost of goods increases.
OC. The cost of goods stays the same.
OD. The cost of goods varies.
Answer:
The answer is B
Explanation:
Generally speaking, a company selling goods during periods of inflation will see an increase in its cost of goods sold.When inflation increases, the cost of goods increases. The correct option is B.
Generally speaking, inflation raises the price of products sold. The price of producing and purchasing those things rises together with the prices of goods and services owing to inflation.
This can be attributable to elements like escalating manufacturing costs, rising input costs, and shifting dynamics of supply and demand.
As a result, companies might need to modify their pricing plans to take inflation-related cost increases into account, the cost of goods typically increases when inflation occurs.
Thus, the correct option is B.
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Sound waves move the most quickly through which materiel?
A. Water
B. Iron
C. Milk
D. Air
Explain how fusion and fission are similar to and different from each other at the atomic level. Explain which
process is currently used at most nuclear power plants around the world and which process occurs on the sun.
Please helpp
Nuclear fusion and fission involve changes in the nucleus of atom, but nuclear fission is most in employed nuclear power plants around the world whereas fusion occurs on the sun.
What are nuclear fission and fusion reactions?
Nuclear fission is a reaction in which the nucleus of large atoms are split into nuclei of two or more smaller atoms.
Nuclear fusion is a reaction in which nuclei of two or more smaller atoms are combined to give an atom of larger nucleus.
Large amounts of energy are involved in both reactions.
The Sun produces energy by nuclear fusion.
However, the most commonly employed method in nuclear power plants is nuclear fission because the necessary conditions required for nuclear fusion have not being developed currently.
Therefore, nuclear fusion and fission involve changes in the nucleus of atom, but nuclear fission is most in employed nuclear power plants around the world whereas fusion occurs on the sun.
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Where are heavier elements, like iron or gold made?
*
1 point
In space, between the stars
in the black holes at the centers of galaxies
In the hearts of stars
They were made as part of the big bang
Answer:
In the hearts of stars:
Theory tells us the elements heavier than iron are created by novas
that is when a star explodes, and any heavier elements were once created when a star exploded.
Why is a Magnetar extremely magnetic?
Answer:
The dominant theory of the strong fields of magnetars is that it results from a magnetohydrodynamic dynamo process in the turbulent, extremely dense conducting fluid that exists before the neutron star settles into its equilibrium configuration.
How strong is a magnetar magnetic field?
It can generate the most intense magnetic field observed in the Universe. The field strength of a magnetar is one thousand trillion times stronger than Earth's and is so intense that it heats the surface to 18 million degrees Fahrenheit. We only know of about 10 magnetars in the Milky Way galaxy.
To help you rank the reactivity of the three metals you will be creating atomic charge models for each of the elements. You may use the periodic table as a model to help you complete these individual models.
1. Complete the atomic charge models to show the charged substructure of sodium, magnesium and potassium.
Metals tend to readily lose electrons and form cations. Most of them react with atmospheric oxygen to form metal oxides. However, different metals have different reactivities towards oxygen (unreactive metals such as gold and platinum do not readily form oxides when exposed to air
For sodium
Nucleus =11+Core electrons=10-Valence electrons=1-For Magnesium
Nucleus=12+Core electrons=10-Valence electrons=2-For potassium
Nucleus=19+Core electrons=18-Valence electrons=1-a metallic surface is illuminated with light of wavelength 400 nm. if the work function for this metal is 2.4 eV. what is the maximum kinetic energy of the ejected electrons, in electron volts?
Assume that
1 eV = 1.6 * 10^-19
c = 3 * 10^8
h = 6.626 * 10^-34
I already got the answer before and I know that the max kinetic energy is 0.71 eV but when I tried to solve it again, I forgot what to do.
I tried getting the cut off wave lengths and using that combined with the wavelength provided to get the K.E max but it didn't work
The maximum kinetic energy of the ejected electrons will be 0.71 eV.
What is the kinetic energy of electrons?The kinetic energy (KE) of electrons is defined as the product of one-half of the mass of the electron to the square of the velocity at which electrons spin in orbit.
Given data;
λ(Wavelength)= 400 × 10⁻⁹ m
Φ(Work function)=2.4 eV
c(Speed of light)= 3 ×10⁸ m/sec
h(Constant) = 6.626 * 10^-34
[tex]\rm \phi = 2.4 eV = 2.4 \times 1.6 \times 10^{-19} \\\\ \rm \phi =3.84 \times 10^{-19} \ J[/tex]
The maximum kinetic energy is found as;
[tex]\rm KE= \frac{hc}{\lambda} - \phi \\\\ KE= \frac{6.64 \times 10^{-34}}{400 \times 10^{-9}} -3.84 \times 10^{-19} \\\\ KE=1.14\times 10^{-19} \ J[/tex]
Unit conversion:
1 eV = 1.6 * 10⁻¹⁹ j
1 J=1/( 1.6 * 10⁻¹⁹) ev
KE=0.71 eV
Hence, the maximum kinetic energy of the ejected electrons will be 0.71 eV.
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Decide whether the following statement is true (T) or false (F).
Original seat belt designs were 2-point or lap belts
1. True
or
2. False
I really hope this is true. also pay no attention to this answer I'm doing it to finish my account
Answer:
True
Explanation:
See picture.
A crate is moved across a frictionless floor by a rope THAT is inclined 30 degrees above horizontal. The tension in the rope is 50 N. How much work is done in moving the crate 10 meters?
Only the horizontal component of the tension force is performing work on the crate. This component has magnitude (50 N) cos(30°) = 25√3 N, so the work done is
(25√3 N) (10 m) = 250√3 N•m ≈ 433 J
When electromagnetic radiation strikes perpendicular to a flat surface
Answer:
a totally absorbing surface feels radiation pressure
Explanation:
When electromagnetic radiation strikes perpendicular to a flat surface, a totally absorbing surface feels radiation pressure
A stunt pilot in an air show performs a loop-the-loop in a vertical circle of radius 3.80 103 m. During this performance the pilot whose weight is 623 N, maintains a constant speed of 2.10 102 m/s. (a) When the pilot is at the highest point of the loop determine his apparent weight in N. N (b) At what speed, in m/s, will the pilot experience weightlessness
The apparent weight of the pilot would be 619.48 N and the speed he would experience at weightlessness is 192. 97 m/s
What is apparent weight?
Apparent weight is a property of object that co-relates to the heaviness of the object.
It differs from the weight of an object as a result of the in-balance between the force acting on the object and an equal but opposite force
How to calculate the apparent weight
Formula:
Apparent weight = Real weight (mg) - m v∧2 ÷ r
Where m = mass
g = acceleration due to gravity = 9.8 m/s²
v = constant velocity = 2. 10 × 10∧2 m/s
r = radius = 3.80 × 10∧3 m
Note that weight = mg
m = weight ÷ g = 623 ÷ 9.8 = 63. 57 kg
a. Apparent wieight = 623 - (63. 57 × 2.10 × 10∧2 × 2.10 × 10∧2) ÷ 3.80 × 10∧3)
= 623 - (63.57 × 210) ÷ 3800
= 623 - 13377 ÷ 3800
= 623 - 3. 52
= 619.48 N
b. At weightless, weight = 0
Speed, V = √g× r = √ 9.8 × 3800 = √37,240 = 192. 97 m/s
Hence, The apparent weight of the pilot would be 619.48 N and the speed he would experience at weightlessness is 192. 97 m/s
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What is conflict resolution?
A.) committing to fair play
B.) settling a dispute or disagreement
C.) working toward a common goal
D.)trying your best to win
Answer:
B) Settling a dispute or disagreement
Explanation:
A conflict is a disagreement or argument between opposing parties.
A resolution is a solution to a problem.
Knowing both these definitions, the answer choice that makes the most sense would be B) Settling a dispute or disagreement.
Hope this helps!!
Which optical device can focus light to a point through reflection?
Answer:
A
Explanation:
did the quiz
Answer:
A
Explanation:
What is the period of a wave that has a frequency of 300 hz?
Answer:
T = 0.003 s
(Period is written as T)
Explanation:
Period = time it takes for one wave to pass (measured in seconds)
frequency = number of cycles that occur in 1 second
(measured in Hz / hertz / 1 second)
Period : T
frequency : f
So, if we know that the frequency of a wave is 300 Hz, we can find the period of the wave from the relation between frequency and period
T = [tex]\frac{1}{f}[/tex] f = [tex]\frac{1}{T}[/tex]
to find the period (T) of this wave, we need to plug in the frequency (f) of 300
T = [tex]\frac{1}{300}[/tex]
T = 0.00333333333
So, the period of a wave that has a frequency of 300 Hz is 0.003 s
[the period/T of this wave is 0.003 s]
Why is it making me do this
Answer:
I don't know.
Explanation:
I have no idea what you are referring to.
Question 1 of 10
What is the wavelength of a wave with a frequency of 262 Hz and a speed of
343 m/s?
O A. 1.3 m
OB. 89,866 m
O C. 1.11 x 10-5 m
O D. 0.76 m
SUBMIT
Answer:
V = λ f (wavelength * frequency)
λ = V / f = 343 m/s / 262 / s = 1.3 m