sue and betti both ski straight down a hill, both starting from rest. sue weighs more than betti. neglecting friction and wind resistance, which skier will be moving the fastest at the bottom of the hill?
Answer:
They are both moving at the same speed since they will have the same acceleration
F = M a describes acceleration
M a = M g sin theta where theta is the slope
One can easily see that
a = g sin theta and the weight does not enter into the equation
Is the image formed by a plane mirror always real?
True or false?
What is chemical reaction? Give an example of each of exothermic and endothermic reaction
Answer:
A chemical reaction is a process that occurs when two or more molecules interact to form a new product(s).
Endothermic reactions are chemical reactions in which the reactants absorb heat energy from the surroundings to form products.
Example:
A popular example of an endothermic chemical reaction is photosynthesis. During this process, plants absorb energy from the Sun and convert it into carbon dioxide and water into glucose and oxygen.
An exothermic reaction releases energy into the surrounding of the system.
Example:
the chemical reaction between sodium and chlorine results in the formation of sodium chloride (also known as common salt).
Snow on the ground prevents polar climate systems from gaining heat by what mechanism?
Question 7 options:
Heating by greenhouse gases
Snow reflecting solar radiation
Heat spread from the equator
Release of heat from Earth's core
The characteristics of the thermal heating mechanisms allow to find the correct answer for how snow prevents soil heating is:
b) Snow reflecting solar radiation.
The heating of the system occurs by absorption of energy by three basic mechanisms:
Conduction. It occurs when the bodies are in constant and energy is transferred by the oscillations of the elements of the body, but there is no physical displacement of parts of it. Convection. This mechanism occurs mainly with liquid and gases, it is due to the displacement of masses of the element due to its greater energy. Radiation. In these mechanisms there is no physical contact and the energy is transferred by the emission of electromagnetic waves.
In this case, the snow receives electromagnetism waves from the sun, a large part of these waves are reflected by the snow, therefore they do not reach the ground and cannot be absorbed, thus decreasing its heating.
Let's analyze the claims:
a) False. Greenhouse gases do not interfere with snow on the ground.
b) True. This mechanism reduces radiation heating.
c) False. The heat that comes from the equator warms the air.
d) False. Heating by the Earth's core occurs everywhere and comes from the center of the earth, so it does not interact with snow.
In conclusion, with the characteristics of the thermal heating mechanisms, we can find the correct answer for how snow prevents soil heating is:
b) Snow reflecting solar radiation
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a flashlight operates with a current of 3.0 a and a power of 4.5 W. what is the voltage of the flashlights battery?
Answer:
V=1.5V
Explanation:
p=I×V
4.5=3×V
[tex]v = \frac{4.5}{3} [/tex]
[tex]v = \frac{3}{2} [/tex]
v=1.5
A moving car hits the breaks and starts to slow down. The car was moving 35 m/s when hitting the breaks and slows at a rate of 7 m/s/s. What is the final velocity of the car after 4 seconds?
7 miles per second.
It would take 5 seconds to stop because 35 divided by 7 = 5.
It would slow 28 miles in 4 seconds because 7 x 4 = 28.
35 - 28 = 7.
if the wave velocity and frequency of a wave are both doubled, the wavelength is
If the wave velocity and frequency of a wave are both doubled, the wavelength will remain the same.
The wavelength of a wave shows the spatial orientation of distance between two successive crest in a wave medium.
The wavelength λ is expressed by using the relation:
[tex]\mathbf{\lambda = \dfrac{v}{f}}[/tex]
Now, if velocity and frequency of wave is both doubled, the wavelength will remain the same.
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Preston goes on a camel safari. There, he travels 5 km north, then 3 km east.
7777Answer:
Explanation:
What is the relationship between transit duration and orbital period?
Answer:
The length of time between each transit is the planet's "orbital period", or the length of a year on that particular planet. Not all planets have years as long as a year on the Earth! Some planets discovered by Kepler orbit around their stars so quickly that their years only last about four hours!
I hope it helps.
Answer:
lenght of year poExplanation:
hope it helpsJoey is performing an experiment in science class. He mixes two liquids in a test tube, and gas bubbles
appear at the surface of the test tube. Which of the following describes what is most likely taking place?
a.) A physical change is causing a change the phase from liquid to gas.
b. A chemical change has caused the liquids to undergo combustion and gas is escaping.
c. A physical change is causing the isolation to exhibit different properties than the original
substances.
d. A chemical change has resulted in the production of a new substance, which is being given off
as gas.
Answer:
The answer is D
Explanation:
Gas is made when chemical change happens. The chemical change has made a new substance gas. It cannot be combustion unless it is hot or was on fire.
A chemical change has resulted in the production of a new substance, which is being given off.
The correct option is D.
What is called chemical change?A chemical change is any process that converts one material into another, produces new compounds with unique features, or combines any of these processes. When two compounds combine to generate a new material, it takes place (synthesis or either decomposes to form more substances).
What takes place when chemicals change?Breaking covalent bond between reactant molecules (particles) and creating new bond between atoms in product particles are two aspects of chemical reactions (molecules). While there are the same number of atoms both before and after the biochemical transition, there will be a change in the number of molecules.
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(a) One medium is air, in which the speed of light is 3.00 x 108 m/s. The other
medium is ice, in which light has a speed of 2.29 x 108 m/s. Use this information to
identify medium A and medium B. Explain
Answer:
WARNING WRONG SPELLING.that is a ternadow and very dangeruse air .What is kinematics . Give two examples
Answer:
kinematics explains the terms like acceleration, velocity, and position of the objects while in motion.
Some important parameters in kinematics are displacement, velocity, and time.
Explanation:
your welcome,can you give me the brainliest? plssss
thank me if it was correct for you too.
Answer:
Definition of Kinematics :- Kinematics is the study of the motion of mechanical points, bodies and systems without consideration of their associated physical properties and the forces acting on them. ... An example model of bodies in a system is the gears in a vehicle's transmission.Example of kinematics :- The examples for kinematics are given below: -i) Moving train and bus. ii) Motion of a mass on inclined plane. iii) Running water in the river. iv) Falling water from a mountain peak.Explanation:
Hope this helps you dear ✌️Carry on learning !!what happens to light when it travels from air into water
Answer:
Water is more dense than air. When water goes through a denser thing, the light is "bent" more towards the "normal" which is a straight, vertical line.
Follow me on i n s t a g r a m, message me and I'll follow you back: ifaulkner24
friction and normal force are examples of
Answer:
Friction is a force that tends to oppose the relative motion between two bodies in contact. Frictional force always acts on a moving body from the direction opposite to the direction of motion. It opposes the motion, and therefore, helps to reduce the speed of the moving object. It is a contact force.
What are some of the dangers that volcanoes pose to human populations? a. Destruction of property from lava flow b. Destruction from mud flows c. Lung problems from ash and toxic gases d. All of the above.
Destruction of property from lava flow, destruction from mud flows and lung problems from ash and toxic gases are all some of the dangers that volcanoes pose to human populations.
Volcanoes refer to an opening that appears on the earth's surface and serves as a vent for lava, volcanic ash, and gases. These could lead to a fire outbreak in mountains sometimes.
The following are dangers posed by volcanoes pose to human populations;
Destruction of property from lava flow Destruction from mud flowsLung problems from ash and toxic gasesHence, the correct answer to the question is "all of the above".
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Answer:
D
Explanation:
EDGE 2021
Please answer all questions if you do I mark you
Explanation:
1. A
2. B
3. I don't know this one but my guess is b
1 point
A hairdryer uses 10 A of current when plugged into a 120 V outlet. How
much power does it use?
Answer:
1200 watt
Explanation:
P= I*V=10*120=1200watt
if you immerse an object into a known mass of water, the measured mass of the water will _____, and will be equal to the mass of the water displaced by the immersed object.
Answer: decrease
Explanation: it does
A young diver is practicing his skills before an important team competition. Use the diagram below in order to analyze the energies of the diver and complete the statements below.
Where m = mass (kg), g = 9.8 m/s2, v = velocity (m/s), h = height (m), KE = kinetic energy (J), and GPE = gravitational potential energy (J).
Use the equations above to answer the following questions.
A diver with a mass of 90 kg is at a height of 10 m, and he has not jumped off of the board yet (v = 0 m/s). When the diver reaches a height of 5 m (Point C), his gravitational potential energy is
A. 1350 J
B. 8820 J
C. 4410 J
D. 0 J
and his velocity is
E. 4.5 m/s
F. 0 m/s
G. 3.2 m/s
H. 9.9 m/s
Please help will mark brainliest
[tex]\\ \sf\longmapsto GPE=mgh[/tex]
[tex]\\ \sf\longmapsto GPE=90(5)(9.8)[/tex]
[tex]\\ \sf\longmapsto G PE=4410J[/tex]
Now
It's converted to kinetic energy while reaching ground.
[tex]\\ \sf\longmapsto K.E=4410[/tex]
[tex]\\ \sf\longmapsto \dfrac{1}{2}mv^2=4410[/tex]
[tex]\\ \sf\longmapsto 90v^2=8820[/tex]
[tex]\\ \sf\longmapsto v^2=98[/tex]
[tex]\\ \sf\longmapsto v=9.9m/s[/tex]
Done
Answer:
Hope it will help you a lot.
The mass of a water skier is 54 kg. Calculate his/her weight if the gravitational field strength is 10 N/kg.
Answer:
weight=mass×gravity
the mass in this question is 54kg and the gravity is 10
therefore:
w=54×10
=540N
I hope this helps
You roll a toy car, and it moves 10 meters in five seconds. What is the car's velocity?
The car's velocity is 2 m/s.
Hope you could get an idea from here.
Doubt clarification - use comment section.
An object is dropped from a 42 m tall building. How long does it take to reach the ground?
Answer:
2.1 seconds
Explanation:
let D represent the height in meters
let g represent gravity in meters per second squared
let t represent time in seconds
D= -42 meters (negative because it falls down)
g= -9.8m/s^2
t= [tex]\frac{-42 meters}{9.8 m/s^2}[/tex]
this gives t= 4.2857 s^2
the meter units cancel out in the division
now we must simplify the units to singular seconds so...
[tex]\sqrt{4.3 s^{2} }[/tex] which simplifies to [tex]\sqrt{4.3}[/tex] x [tex]\sqrt{s^{2} }[/tex]
this equals 2.1 seconds
The parking brake on a 1200kg automobile has broken, and the vehicle has reached a momentum of 7800kg.m/s. What is the velocity of the vehicle?
Answer:
Velocity of the vehicle (v) = 6.5 m/s
Explanation:
Mass of automobile (m) = 1200 kg
Momentum of vehicle (p) = 7800 kg m/s
By using formula of momentum:
[tex] \rm p = mv \\ \rm 7800 = 1200 \times v \\ \rm v = \frac{7800}{1200} \\ \rm v = 6.5 \: m {s}^{ - 1} [/tex]
1. Which statement is true about natural
resources?
A. They are only found in living things.
B. They only provide sources of food and
material to humans.
C. They can be man-made or found in nature.
D. They can be a substance, material, object or
source of energy.
2. How do the properties of a substance that is
the result of a chemical reaction compare to the
properties of the starting material?
A. The properties will stay the same.
B. The properties will be different.
C. The properties stayed the same and new
properties will be added.
3. Chlorine is a poisonous gas. Sodium reacts
explosively with water. When chlorine and
sodium react with each other, the product is
the salt we sprinkle on our food. Which
principle does this demonstrate?
A. Reactants are more dangerous than products.
B. Energy is released by some reactions and
absorbed by others.
C. When two reactants form one product, the
reaction is spontaneous.
Answer:
1. D. They can be a substance, material, object or source of energy.
2. B. The properties will be different.
3. C. When two reactants form one product, the reaction is spontaneous.
on what factors does the quantity of heat of an object depend
Answer:
The quantity of heat given to body depends on: (i) The mass of the body, (ii) The rise (or fall) in the temperature of the body, and (iii) Nature of the material of the body.
Explanation:
Hope this helps
have a great day
~Zero
PLEASE HELP!! WILL GIVE BRAINLIEST IF YOU SHOW WORK. ITS DUE SOON :(
If the radius of the CD below is 6.0 cm and the angular velocity is 5.0 rad/s, what is its angular displacement in 2.0 s? What is it's Linear displacement on the edge in 2.0 s? Please show work :(
Answer:
theta = ω t = 5.0 / sec * 2 s = 10 rad
S = R theta = 6 cm * 10 rad = 60 cm
The angular displacement of CD if the radius of the CD below is 6.0 cm and the angular velocity is 5.0 rad/s, is 10 rad, and the linear displacement is 60 cm.
What is velocity?When anything is moving, its velocity tells us how quickly that something's location is changing from a certain vantage point and as measured by a particular unit of time.
If a point moves along a path and covers a certain distance in a predetermined amount of time, its average speed over that period of time is equal to the distance covered divided by the travel time. A train traveling 100 kilometers in two hours, for instance, is doing it at an average speed of 50 km/h.
Given:
The radius of the CD, r = 6 cm,
The angular velocity, v = 5 rad / sec
The time, t = 2 sec,
Calculate the angular displacement by the formula given below,
[tex]v = s / t[/tex]
5 = s / 2
s = 10 rad,
Calculate the linear displacement by the formula given below,
Linear displacement = [tex]r\ s[/tex]
Linear displacement = 6 × 10
Linear displacement = 60 cm
Therefore, the angular displacement of CD if the radius of the CD below is 6.0 cm and the angular velocity is 5.0 rad/s, is 10 rad, and the linear displacement is 60 cm.
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What is the mass of a box if it accelerated 5 m/s from a force of 12 N?
Answer:
60
Explanation:
You multiply the acceleration and the force and you get your answer
9. When a balloon rises into the air, it
A. Expands on cooling
B. Contracts on cooling
C Expands on heating
D. Contracts on heating
Answer:
Answer 3: When a balloon goes up higher in the air, its size will increase. Since there's less air in the upper atmosphere, there's less stuff pushing back on the balloon, and hence the pressure is lower, which allows the balloon to expand
Answer: C
Explanation:
As the balloon rises, the gas inside the balloon expands because the atmospheric pressure surrounding the balloon drops. The atmosphere is 100 to 200 times less dense at the float altitudes than on the ground. and as the air is heated inside the balloon it causes it to rise upwards (because it is lighter than the cooler air on the outside). When the pilot needs to bring the balloon down again, he simply reduces the temperature of the air inside the balloon causing it to slowly descend.
7. If the speed of light in medium-1 and medium-2 are 2.5x 10 m/s and 2x 10 m/s respectively then the refractive index of medium-1 with respect to medium-2 is (a) 3/2.5 (b) 2/2.5 (c) 2.5/3
Answer:
Answer to the question is 4 / 5
To know the answer with proof see the above attachmentExplain how the stars impact the shape of a galaxy.
Answer:
Galaxies are too far away for astronomers to take real 3D measurements, but we can infer their shape based on the movement of stars. ... This is also true of less common spiral galaxies like the Milky Way. The bulge near the center contains older stars, while the flattened arms are home to younger ones.
Explanation:
The orbits of stars can also affect the shape of a galaxy through a variety of density waves that are produced when material is compressed into something comparable to a traffic jam in galaxies.
What is Star?A star is defined as a celestial object consisting of a luminous sphere of plasma held together by self-gravity where the closest star to Earth is the Sun. While many other stars are visible to the uncovered eye at night, their extreme distance from Earth causes them to appear as fixed points of light.
Galaxies are too far away for astronomers to take true 3D measurements, through which we can estimate their size based on the motion of stars, which is also true for less common spiral galaxies like the Milky Way.
Thus, the orbits of stars can also affect the shape of a galaxy through a variety of density waves that are produced when material is compressed into something comparable to a traffic jam in galaxies.
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