Which statement describes the difference between metallic bonds and Van der Waals forces
Explanation:
Metallic bonds hold metal atoms and freely moving valence electrons together, while Van der Waals forces hold nonpolar molecules together. OD. Metallic bonds hold metal atoms and freely moving valence electrons together while Van der Waals forces hold atoms together when they share valence electrons.
Assume you have a person with a mass of 65 kg riding a skateboard down a ramp. While they are
still 4.8 m high, they are traveling at a speed of 8.0 m/s.
a) Calculate the Eg. [write here)
b) Calculate theEk [write here]
c) Calculate the Etotal. [write here]
d) If the ramp had a total height of 8.0 m, what would be their Eg, Ek, and Etotal at that height?
Answer:
a) Eg = 3,060.72 j
b) Ek = 2,080 j
c) Etotal = 5,140.72 j
d) Eg = 5,140.2 j
Ek = 0 j
Etotal = 5,140.2 j
Explanation:
The given parameters of the person riding the skateboard are;
The mass of the person, m = 65 kg
The height of the person (above ground level), h = 4.8 m
The speed at which the person is traveling, v = 8.0 m/s
a) The gravitational potential energy, Eg = m·g·h
Where;
m = The mass of the object at the given height = 65 kg
g = The acceleration due to gravity, g ≈ 9.81 m/s²
h = The height by which the object is elevated = 4.8 m
∴ Eg = 65 kg × 9.81 m/s² × 4.8 m = 3,060.72 joules
The gravitational potential energy, Eg = 3,060.72 J
b) The kinetic energy, Ek, is given as follows;
Ek = 1/2·m·v²
Where;
v = The velocity of the object = 8.0 m/s
∴ Ek = 1/2 × 65 kg × (8.0 m/s)² = 2,080 joules
The kinetic energy, Ek = 2,080 J
c) The total mechanical energy, Etotal = Eg + Ek
∴ Etotal = 3,060.72 j + 2,080 j = 5,140.72 J
The kinetic energy, Ek = 5,140.72 J
d) If the ramp had a total height of 8.0 m, we have;
At the 8.0 m height
Etotal = Eg(max), Ek = 0 j
With the given values, we get;
Eg(max) = 65 kg × 9.81 m/s² × 8 m = 5,101.2 joules = Etotal
Eg(max) = 5,101.2 j
Etotal = 5,101.2 j
Ek = 0 j
However, using only the values in the question with the assumption that all things being equal, we have;
Etotal = Constant = 5,140.72 j
Eg a the max height, 8.0 m = Eg(max) = Etotal = 5,140.2 j
Ek = 0 j
Which of the following are devices that utilize electromagnets? Select all that apply?
relay switches
doorbells
crane pulleys
security locks
When serving you start on the right and must hit to which designated area?
- right side you are looking at
- left side you are looking
- any place over the net
(pickle ball)
you can serve to anyplace over the net
During which process does layer upon layer of sediment build up, exerting pressure on the layers below?
a. erosion
b. compaction
c. conglomerate
d. weathering
These 2 processes cause watersheds to change.
Answer:
Change is an integral component of the watershed. The wide variations in river and stream flow regularly change shorelines, stream channels and stream corridors. Upland areas of watersheds also undergo changes due to ecological succession, disease, competition, human activity and other factors.
Explanation:
A KG object has a speed of 24 M/S if it has 14 J of kinetic energy what is the mass
someone please help I have no idea what to do
Answer:
10⁶ or 1000000
Explanation:
formula: frequency = velocity/wavelength = [tex]\frac{3.0x10^{8} }{3.0x10^{2}}[/tex]i'm not sure because the teacher probably wrote the question wrong.an electric bulb is marked 40volts ,230w another bulb is marked 40w,110v
a.calculate the ratio of their resistance
b.the ratio of their energy
c.find the charge on each bulb
d.which of the two bulbs can hold enough .
Answer:
a. The ratio of their resistance is 2783:64
b. The ratio of their energy is 4:23
c. The charge on the first bulb is 5.75 C
The charge on the second bulb is [tex]0.\overline {36}[/tex] C
Explanation:
The voltage on one of the electric bulbs, V₁ = 40 volts
The power rating of the bulb, P₁ = 230 w
The voltage on the other electric bulbs, V₂ = 110 volts
The power rating of the bulb, P₂ = 40 w
a. The power is given by the formula, P = I·V = V²/R
Therefore, R = V²/P
For the first bulb, the resistance, R₁ = 40²/230 ≈ 6.96
The resistance of the second bulb, R₂ = 110²/40
The ratio of their resistance, R₂/R₁ = (110²/40)/(40²/230) = 2783/64
∴ The ratio of their resistance, R₂:R₁ = 2783:64
b. The energy of a bulb, E = t × P
Where;
t = The time in which the bulb is powered on
∴ The energy of the first bulb, E₁ = 230 w × t
The energy of the second bulb, E₂ = 40 w × t
The ratio of their energy, E₂/E₁ = (40 w × t)/(230 w × t) = 4/23
∴ The ratio of their energy, E₂:E₁ = 4:23
c. The charge on a bulb, 'Q', is given by the formula, Q = I × t
Where;
I = The current flowing through the bulb
From P = I·V, we get;
I = P/V
For the first bulb, the current, I = 230 w/40 V = 5.75 amperes
The charge on the first bulb per second (t = 1) is therefore;
Q₁ = 5.75 A × 1 s = 5.75 C
The charge on the first bulb, Q₁ = 5.75 C
Similarly, the charge on the second bulb, Q₂ = (40 W/110 V) × 1 s = [tex]0.\overline {36}[/tex] C
The charge on the second bulb, Q₂ = [tex]0.\overline {36}[/tex] C.
d. The question has left out parts
Which of the following refers to the concentration of a substance?
A.the maximum amount of a solute that can be dissolved in a solvent at a given temperature
B.the minimum volume of solvent dissolved per liter of solution at a given pressure
C.the grams of solute dissolved per 100 g of solvent
D.the size of the particles that make up a substance
The statement which refers to the concentration of a substance is the maximum amount of a solute that can be dissolved in a solvent at a given temperature. Thus, the correct option for this question is A.
What is a Substance?A substance may be defined as a type of chemical element and its compounds in the natural state or the result of a manufacturing process. In a manufacturing process, a chemical reaction is usually required in order to form a substance.
The concentration of a substance is the quantity of solute present in a given quantity of solution. Concentrations are usually expressed in terms of molarity, defined as the number of moles of solute in 1 L of solution.
Therefore, the maximum amount of a solute that can be dissolved in a solvent at a given temperature is a statement that refers to the concentration of a substance. Thus, the correct option for this question is A.
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principle of quantization of charge
Answer:
Quantization is the process of replacing analog samples with approximate values taken from a finite set of allowed values.
Explanation:
What does the object below model?
O A. The heart
O B. The skeletal system
C. The brain
O D. The lungs
Answer: c
Explanation: it is c because i used my brain to answer it
Answer: The Brain
Explanation:
Its the brain
A small block with mass 0.0350 kgkg slides in a vertical circle of radius 0.550 mm on the inside of a circular track. During one of the revolutions of the block, when the block is at the bottom of its path, point AA, the magnitude of the normal force exerted on the block by the track has magnitude 3.90 NN . In this same revolution, when the block reaches the top of its path, point BB, the magnitude of the normal force exerted on the block has magnitude 0.670 NN . Part A How much work was done on the block by friction during the motion of the block from point AA to point BB
Answer:
W_net = μ 5.58, μ = 0.1 W_net = 0.558 J
Explanation:
The work is defined by the related
W = F. d = F d cos θ
where bold indicates vectors.
In the case, the work of the friction force on a circular surface is requested.
The expression for the friction force is
fr = μ N
the friction force opposes the movement, therefore the angle is 180º and the cos 180 = -1
W = - fr d
the path traveled half the length of the circle
L = 2 π R
d = L / 2
d = π R
we substitute
W = - μ N d
Total work is initial to
W_neto = - μ π R (N_b - N_a)
let's calculate
W_net = - μ π 0.550 (0.670 - 3.90)
W_net = μ 5.58
for the complete calculation it is necessary to know the friction coefficient, if we assume that μ = 0.1
W_net = 0.1 5.58
W_net = 0.558 J
I’m giving 15 points for this one multiple choice question! Pls Help! It’s not A.
An electric food processor uses 250 joules of electrical energy every second. Due to friction and other causes, the energy available to spin the blades to cut food is reduced to 200 joules per second. The efficiency of the food processor is
A. 0.8%
B. 8%
C. 80%
D. 800%
Ava learns in her science class that the Sun is much larger than the Moon. When she looks at the Sun and the Moon in the sky, however, they appear to be about the same size. Which of the following best explains why this is true?
A.
The Moon is much older than the Sun.
B.
The Moon shines more brightly than the Sun.
C.
The Moon is much farther away from the Earth than the Sun is.
D.
The Moon is much closer to the Earth than the Sun is.
i need help asap !
Work output has a force of 5 N and distance of 5 m. Work input has a force of 10 N and distance of 10 m. What is the efficiency?
100%
25%
125%
0.25%
Answer:
the answer is 100%!
your welcome
Water tends to moderate climate. Why is it warmer in the winter and cooler in the summer in cities located near the ocean or large lakes?
A.Water has a low specific heat and therefore changes temperature faster than most other substances.
B.Water has a low specific heat and therefore changes temperature slower than most other substances.
C.Water has a high specific heat and therefore changes temperature more slowly than most other substances.
D.Water has a high specific heat and therefore changes temperature more quickly than most other substances.
It is warmer in the winter and cooler in the summer in cities because water has high specific heat and therefore changes temperature more slowly than most other substances. The correct option is C.
What is climate?Climate is the average weather over a longer period of time in a particular area. A description of a climate includes details such as the typical temperature in each season, the amount of rainfall, and the amount of sunshine.
Coastal weather tends to be more moderate than continental weather, with fewer hot and cold extremes, because the ocean warms and cools more slowly than the atmosphere.
The majority of rain clouds are produced by ocean evaporation, particularly in the tropics, which affects where wet and dry regions on land are located.
Therefore, the correct option is C. Water has a high specific heat and therefore changes temperature more slowly than most other substances.
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Which statement compares the strengths of electric forces between particles of matter?
Please don't just guess for points, if your answer is wrong i'll report it.
A. Hydrogen bonds are stronger than ionic bonds but weaker than Van der Waals forces.
B. Metallic bonds are stronger than hydrogen bonds but weaker than ionic bonds.
C. Hydrogen bonds are weaker than Van der Waals forces but stronger than metallic bonds.
D. Metallic bonds are weaker than hydrogen but are stronger than ionic bonds.
B. Metallic bonds are stronger than hydrogen bonds but weaker than ionic bonds.
The statement is discussing the relative strengths of different types of electric forces that can exist between particles of matter.
Metallic bonds are formed by the sharing of electrons between atoms in a metal, and are considered relatively strong. Hydrogen bonds are formed between molecules that contain hydrogen and are relatively weak compared to metallic bonds.
Ionic bonds are formed between positively and negatively charged ions and are generally considered to be the strongest of these three types of bonds. Thus, the statement concludes that metallic bonds are stronger than hydrogen bonds but weaker than ionic bonds in terms of their relative strengths.
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What are two ways fusion is used in the real world.
Answer:
The main application for fusion is in making electricity. Most fusion reactors make less radiation than the natural background radiation we live with in our daily lives. ... Clean - No combustion occurs in nuclear power (fission or fusion), so there is no air pollution.
what two factors directly affect the acceleration of an object?
The acceleration of an object depends on the mass of the object and the amount of the force applied to it. It states that the acceleration of an object increases with increased force and decreases with increased mass.
A book is placed on a table and a bike moves on a road.
Which statement is correct?
Both the book and the bike have kinetic energy.
Both the book and the bike have potential energy.
The book has potential energy and the bike has kinetic energy.
The book has kinetic energy and the bike has potential energy.
The book has potential energy and the bike has kinetic.
kinetic energy is energy possessed when a object is in motion. The bike is moving. Therefore, it has kinetic energy. The book isn't moving. Hopefully that helped
The Earth's atmosphere is opaque to the
part of the electromagnetic
spectrum
a)
b)
c)
-)
)
0
Visible
Infrared
X-Ray
All of the above
A and Care correct
Band C are correct
Heat flows into a gas in a piston and work is performed on the gas by its surroundings. The amount of work done is equal to the heat added. In this situation,
Answer:
The Internal energy of the gas did not change
Explanation:
In this situation the Internal energy of the gas did not change and this is because according the the first law of thermodynamics
Δ U = Q - W ------ ( 1 )
Δ U = change in internal energy
Q = heat added
W = work done
since Q = W. the value of ΔU will be = zero i.e. No change
Please ans fast I will mark brainliest
For sure
In the analogy for how a wave travels along a line of dominoes standing on end, each domino represents___________.
Answer:
im 99% sure its initial disturbance
Explanation:
can someone help me plz
Answer:
Positive I believe... because if you drop it it is negative so picking up a book means positive. thanks for the points though!
Explanation:
Can I have brainliest please? <3
A man lifts a 5 Newton bag of groceries
from the floor to the top of the countertop,
which is 1.1 meters tall. What is the work
done by this person in lifting groceries?
5
5.5
4.5
6
A skateboarder is traveling at a velocity of 8 m/s. She slows down and comes to a stop in 4 seconds. Calculate the skater’s acceleration.
Answer:
Go to this link it has many examples - https://staff.retsd.mb.ca/public/or4xe53elrzxg5ldmjuwe3i/Lists/SharedDocuments/Physics/14.2.PDF
Explanation:
Link ^
Which chemical reaction is the fastest?
A. Mold grows on bread.
B. Bacteria make yogurt from milk.
C. Yeast produces air pockets in bread.
D. Baking soda produces bubbles when vinegar is poured on it.
Answer:
D. Baking soda produces bubbles when vinegar is poured on it.
Explanation:
Acetic acid = C₂H₄O₂
Baking soda = NaHCO₃
C₂H₄O₂ + NaHCO₃ → NaC₂H₃O₂ + H₂O + CO₂
When baking soda is added to vinegar, a chemical reaction will take place producing a huge amount of carbon-dioxide in the form of bubbles in the foaming mixture.
Which of the following is not a unit of volume?
A. L
B. mL
C. m^3
D. cm^2
Explanation:
D. cm^2
It's a unit for quadruple centimeters. All of the others are used to charge the amount of water in a specific bowl etc.