Answer: star A is more luminous
Explanation:
Answer:
B. Star A is more luminous than star B.
Explanation:
on edg
Why is a device never 100% efficient? *
a) Mechanical Advantage
b) Work
c) Friction
d) Speed Ratio
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for science lovers!!
What are the characteristics of a gas ?
Answer:
c no definite shape and volume
The one that is the characteristic of gas is that it has no definite shape or definite volume. The correct option is A.
Gases have a number of distinctive characteristics. The fact that they don't have a set shape means that they can fit into and take on the shape of any container that they occupy.
Due to their high compressibility, gases can occupy a variety of spaces. Because of this, they lack a fixed volume.
Gaseous particles have the potential to disperse and diffuse because they are constantly moving, moving erratically and quickly.
Additionally, compared to liquids and solids, gases have lower densities. They also have traits like high thermal expansion and the capacity to mix and separate with ease.
Thus, the correct option is A.
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A student dips a strip of metal into a liquid. Which is evidence that only a physical change has occurred?
Answer:
not sure if this is correct but it is what i know
The metal bends more easily. The metal changes color. The metal gives off light. The metal gives off heat.
Explanation:
What protects you from getting a shock when you touch a live wire?
A grounding wire
B circuit breaker
C fuse
D insulation
Answer:
Insulation protects you. Thats because the insulation will make a wall almost where the electrons cannot travel through. So when you touch the insulation on a live wire your SAFE. Insulations may include rubber, wood, and air.
Answer:
I'm pretty sure its insulation
Explanation:
A piston has an area of 4 m2 and needs 20 N of force to push it down. What is the pressure?P=F/A *
A) 5 Pa
B) 0.2 Pa
C) 80 Pa
D) 20 Pa
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What would a scientist most likely do to demonstrate the effects of a tsunami? (2 points) construct tsunami models make underwater plates move create actual underwater earthquakes take underwater photographs during a tsunami
Answer:
a - construct tsunami models
Explanation:
scientists cant effect on earthquakes directly, so its not 2 or 3
for 4 it wont help that much to study waves, so its better for them to make model of tsunami waves
A washing machine heats 10kg of water in each wash cycle. How much energy is saved by washing at 30'c instead of 50'c if the starting temperature of the cold water is 16'c? The specific heat capacity of water is 4200 J/Kg'c
The two equations you can use is in the picture.
8.4 × 10⁵ Joules of heat energy can be saved assuming that there is no heat exchange between the washing machine and the environment.
What is Heat energy?Heat energy is the result of movement of tiny particles called as atoms, molecules, or ions in solids, liquids and gas substances. Heat energy can be transferred from one object to another object.
Let m denote the mass of water and the specific heat capacity of water. The energy required to raise the temperature of that much water by would be:
Q = m × c × ΔT
Washing at 30°C would require a temperature change of
ΔT = 30°C - 16°C = 14°C
Washing at 50°C would require a temperature change of
ΔT = 50°C - 16°C = 34°C
In both situations, c = 4.2 × 10³J.kg/ °C while m = 10kg.
Calculate the energy required in either of the situations as:
Washing at 30°C:
Q(30°C) = c × m × ΔT
Q = 4.2 × 10³J.kg/ °C × 10kg × 14°C
Q = 588000 Joules
Washing at 50°C :
Q (50°C) = c × m × ΔT
Q = 4.2 × 10³J.kg/ °C × 10kg × 34°C
Q = 1428000 Joules
1428000 Joules - 588000 Joules = 8.4 × 10⁵ Joules
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In charging by rubbing, electrons move from one material to another because
A. substances with very few neutrons have a net positive charge, so
they get the extra electrons.
O B. heavier substances get rid of electrons so they don't weigh as
much.
O C. the substance with the most protons steals electrons from the
other substance.
O D. some substances hold onto electrons tighter than other
substances, so they get the extra electrons.
Answer: D.
some substances hold onto electrons tighter than other
substances, so they get the extra electrons.
Explanation: When two substances are in contact by rubbing each other, there will be friction between them. The friction will stimulate what we called - Thermal energy. And what thermal energy does is the disrupt the bonding force or enhance it.
We can therefore conclude that some substances hold onto electrons tighter than other substances, so they get the extra electrons. Because at neutral state of the substance, the number of protons is equal to the number of electrons.
Which statement best explains acceleration?
O A.
It is the total distance covered over a period of time.
B.
It is a change in velocity over a period of time.
Oc.
It is a change in displacement over a period of time.
OD.
It is a change in direction over a period of time.
Answer:
It is a change in velocity over a period of time.
Explanation:
It is measured in metres/second2 using an accelerometer.Which of the following statements best describes the second law of
thermodynamics?
A. Heat flows spontaneously from hot to cold, and entropy
decreases.
B. Heat flows spontaneously from hot to cold, and entropy increases.
C. Heat flows spontaneously from cold to hot, and entropy increases.
D. Heat flows spontaneously from cold to hot, and entropy
decreases.
Answer:
B
Explanation:
Heat flows from hot to cold to lower the temperature of hot areas and increase temperature of cold areas. The end result is that the 2 areas have the same temperature, thus increasing entropy.
Heat flows spontaneously from hot to cold, and entropy increases.
The second law of thermodynamics relates to the entropy of a system. According to the second law of thermodynamics, the total entropy of a system may increase or remain constant in a spontaneous process.
The implication of this is that the entropy of a system never decreases. The entropy of a system increases when heat flows from a hot to a cold body and not vice versa.
Hence, the statement that; "Heat flows spontaneously from hot to cold, and entropy increases" describes the second law of thermodynamics.
A ball is thrown upward with ten units of momentum initially. What is the “recoil” momentum of the earth? Why do we not feel this?
Answer:
1.) Momentum = 10 units
2.) Because of gravity
Explanation:
According to the Newton 3rd law of motion, we realise that in collision, momentum is always conserved.
So, if a ball is thrown upward with ten units of momentum initially, the “recoil” momentum of the earth will be approximately 10 units of momentum. We do not feel this because of the gravity.
3.If a force of 12 N is applied to an object with a mass of 2 kg, what will be its acceleration?
Answer:
6 m/s^{2}
Explanation:
The formula for force is
F = mass x acceleration
F = 12 N
mass = 2 kg
So, you can change the formula to solve for acceleration.
acceleration = F / mass
a = 12 N / 12 kg
a = 6 m/s^{2}
which property of substances help to make a thermometer?
I NEED HELP.
Answer:
Mercury
Explanation:
Mercury streches when it is hot so that is why it goes up when the temperature is higher
What is the momentum of a man of mass 10kg when he walks with a uniform velocity of 2m/s.
(point stealers will be reported so pls dont do it)
Answer:
[tex]Momentum(p) = 20kgm/s[/tex]
Explanation:
Given
Mass = 10kg
Velocity = 2m/s
Required
Calculate the momentum of the man
Momentum is calculated as thus
[tex]Momentum(p) = Mass(m) * Velocity(v)[/tex]
or
[tex]p = mv[/tex]
So; to solve this question; we simply substitute 10kg for mass and 2m/s for velocity in the above formula;
The formula becomes
[tex]Momentum(p) = 10kg * 2m/s[/tex]
[tex]Momentum(p) = 10 * 2 * kg * m/s[/tex]
[tex]Momentum(p) = 20kgm/s[/tex]
Hence, the momentum of the man is [tex]20kgm/s[/tex]
1. Suppose you had come along before Mendeleev and were tasked with
organizing the elements into a pattern others could understand. Describe your
arrangement and how you would determine where elements would be placed.
Can you think of any problems your design might create?
2. The first periodic table was organized according to atomic mass, but the
current periodic table is arranged according to atomic number. What is the
difference between atomic mass and atomic number, and why is the atomic
number now the basis for the periodic table?
3. How would the periodic table look differently if it was arranged according to
atomic mass? Focus on Periods 1-4 to complete your answer.
Answer:
1. There would be two different tables, one arranged by mass and the second arranged by the chemical reactions the elements are known for
2. a. The difference is that the atomic mass is fixed and is 2 or more times the atomic number which is variable
b. The atomic number is the bases of the periodic table because it reflects the unique identity as well as the chemical and physical properties of the atoms more than the atomic number
3. The table formed by the atomic mass is not representative of the chemical properties of the elements
Explanation:
1. The elements would have been arranged by mass and by order of reaction such that there would be two tables where the first table will list all the known elements arranged by mass and the second table will group the elements in the order in which they can react or the kinds of compounds they can form such as oxides, nitrides etc
2. a. The atomic number, Z, is determined by the definitive number of protons contained in the nucleus of an atom and it is used for the classification of an atom as a particular element based on the its equivalent atomic number
The atomic number defines the chemical behavior of an an element because it is equal to the number of electrons present in a neutral atom
The atomic mass or mass number, A, is the total of the mass of the protons and the neutrons present in an atom
The neutron is electrically neutral, allowing its quantity to vary without significantly impacting on the chemical behavior of the atom, hence two different elements can have the same number of neutrons
Therefore, the difference is that the atomic mass is fixed and is 2 or more times the atomic number which is variable
b. The atomic number is the bases of the periodic table because it reflects the unique identity as well as the chemical and physical properties of the atoms more than the atomic number
3. If the periodic table was arranged according to the atomic mass, we would have;
Groups
H
He Li B C O F Na
Be N Ne Mg S Ar Sc
O Si Ca Ti Zn Se
It is seen that the above table is not representative of the chemical properties of the elements.
helpp me pleassee....
Answer:
The fundamental wavelength of the vibrating string is 1.7 m.
Explanation:
We have,
Velocity of wave on a guitar string is 344 m/s
Length of the guitar string is 85 cm or 0.85 m
It is required to find the fundamental wavelength of the vibrating string. The fundamental frequency on the string is given by :
[tex]f=\dfrac{v}{2l}\\\\f=\dfrac{344}{2\times 0.85}\\\\f=202.35\ Hz[/tex]
Now fundamental wavelength is :
[tex]\lambda=\dfrac{v}{f}\\\\\lambda=\dfrac{344}{202.35}\\\\\lambda=1.7\ m[/tex]
So, the fundamental wavelength of the vibrating string is 1.7 m.
What is the power of a lightbulb that transfers 60 joules of electrical energy in 15 seconds
Answer:
power=[tex]\frac{work done}{time taken}[/tex]
power=[tex]\frac{60joules}{15seconds}[/tex]
power=4J/s
if you crash your car how could you decrease the damage to you or the car using the concept of impulse
Explanation:
Crumple zones are sections in cars that are designed to crumple up when the car encounters a collision. Crumple zones minimize the effect of the force in an automobile collision in two ways. By crumpling, the car is less likely to rebound upon impact, thus minimizing the momentum change and the impulse.
1/25 force of gravity in distance
Answer: 25
Explanation:
When a shot putter exerts a force of 140 N on a 7.5 kg shot, what its is acceleration?
18.67
Explanation:
acceleration=Force÷mass
acceleration=140÷7.5
acceleration=18.67
Answer:
Explanation:
Force,F = mass,m × acceleration due to gravity,g
⇒g=F/m
⇒g=140/7.5
⇒g=18.67 N/kg
Which situation will the lowest resistance occur
The correct choice is ' C '.
-- Shorter wire has less resistance than longer wire.
-- Thicker wire has less resistance than thinner wire.
-- Colder wire has less resistance than hotter wire.
What is the mass of an object that has a weight of 80.0 N?
Explanation:
SUPONIENDO QUE LA ACELERACIÓN DE LA GRAVEDAD ES [tex]9.80 m/s^{2}[/tex]
USANDO LA SEGUNDA LEY DE NEWTON:
m = 80.0 N/[tex]9.80 m/s^{2}[/tex] = 8.16 kg
Answer:
8kg
Explanation:
using the formula Force(F)=mass(m)×acceleration(a),
since we are finding the mass of the object,we will make m the subject by dividing both sides by a.
you will now get m= f/a
the acceleration on Earth is usually 10m/s
m= 80/10
m= 8/1 which is also 8kg
the force of attraction between two masses is 3.60 Newtons if one of the masses is tripled and the distance between the masses is quadrupled what is the new force of attraction
Answer: F = 19.2 N
Explanation: Given that the initial Force = 3.6N
The formula involved is
F = GMm/r^2
Substitute the force F
3.6 = GMm/r^2
If one of the masses is tripled and the distance between the masses is quadrupled. We have
3.6 = (G × 3Mm)/(4r)^2
Where G will be constant.
3.6 = 3GMm/16r^2
Separate the fraction of number
3.6 = 3/16 × GMm/r^2
Make GMm/r^2 the subject of formula
(3.6 × 16)/3 = GMm/r^2
19.2 = GMm/r^2
Therefore, the new force of attraction is 19.2 N
Variations to the forehand stroke are not allowed. True False
Electron are _____ charged particles
Answer:
negatively
Explanation:
hope this can help u :3
Answer:
negatively
Explanation:
If the box moves at a constant velocity, what do you know about the forces acting on the object?
A)The forces are balanced.
B)The forces are unbalanced.
C)The forces are in outerspace
D)The box has friction
Suppose you roll a bowling ball (m1)down the alley, and the ball strikes the pin (m2) sending it flying. The mass of the bowling ball is greater than the mass of the
pin. Predict the magnitude of the forces between the two objects during the collision
A)The bowling ballexerts a larger force on the pin because it was moving at
a high speed,
B)The pin exerts a larger force on the bowling ball
C)The bowing ball exerts a larger force on the bin because it is more massive
D)Both objects blert the same magnitude of force on each other due to Newtonsard Law
Answer:
The correct option is;
D) Both objects exert the same magnitude of force on each other due to Newton's 3rd law
Explanation:
Newton's third law of motion states that for every action there is an equal and opposite reaction
Since the bowling ball is rolled down the alley while the pin is displaced at such a speed that it flew, we have that the velocity of the rolling ball, v₁ is less than the velocity of the flying pin v₂
Therefore, whereby force = Rate of change of momentum produced we have;
The change of momentum of the ball = m₁×(v₁ - v₁ₐ)
The change of momentum of the pin = m₂×(0 - v₂)
Hence since the pin change in movement (flight) was more suddenly than the slowing down of the ball, the action of the rolling ball is equal to the reaction of the flying pin.
I WILL CHOOSE YOU AS THE BRAINIEST PLEASE ANSWER MY QUESTION
Identify that all objects exert a force of gravity on all other objects in the universe
Answer:
It's like the Earth pulling on you and keeping you on the ground. That pull is gravity at work. Every object in the universe that has mass exerts a gravitational pull, or force, on every other mass. The size of the pull depends on the masses of the objects.
Explanation:
Calculate the wavelength of a nitrogen molecule moving at a speed of 523m/s.
Answer:
The de-Broglie wavelength of the nitrogen molecule is 0.0272 nm
Explanation:
The mass, m, of the nitrogen molecule, N₂ = 14.0076u = 28.0152 × 1.66 × 10⁻²⁷ kg
[tex]v_{rms}[/tex] of N₂ = 523 m/s
The de-Broglie wavelength is given as follows;
[tex]de-Broglie \, wavelength = \dfrac{h}{m\times v_{rms}}[/tex]
Where:
h = Planck's constant = 6.62607004 × 10⁻³⁴ m²·kg/s
Plugging in the values, we have;
[tex]de-Broglie \, wavelength = \dfrac{6.62607004 \times 10^{-34}}{28.0152 \times 1.66 \times 10^{-27}\times 523} = 2.72\times 10^{-11} \, m[/tex]
Hence, the de-Broglie wavelength of the nitrogen molecule = 0.0272 nm.
Which object would have the most kinetic energy?
O A. An elephant sitting at the top of a cliff
B. A sloth hanging from a tall tree
C. A mouse running at 11 km/h
D. A zebra running at 10 km/h
Answer:
D
Explanation:
Answer:
It is D
Explanation:
Because kinetic energy ALSO depends on mass (weight) so it has to be moving and has to have weight in order to be called kinetic energy.
