Answer:
The answer is A. Spokespersons are paid for their testimony. Psueoscience is NOT a real science.
Explanation:
A football is kicked from the ground with a velocity of 38m/s at an angle of 40 degrees and eventually lands at the same height. What is the direction and magnitude of the ball's velocity 0.2 seconds after impact?
Initially, the velocity vector is [tex]\langle 38cos(40^{\circ}),38sin(40^{\circ}) \rangle=\langle 29.110, 24.426 \rangle[/tex]. At the same height, the x-value of the vector will be the same, and the y-value will be opposite (assuming no air resistance). Assuming perfect reflection off the ground, the velocity vector is the same. After 0.2 seconds at 9.8 seconds, the y-value has decreased by [tex]4.9(0.2)^2[/tex], so the velocity is [tex]\langle 29.110, 24.426-0.196 \rangle = \langle 29.110, 24.23 \rangle[/tex].
Converting back to direction and magnitude, we get [tex]\langle r,\theta \rangle=\langle \sqrt{29.11^2+24.23^2},tan^{-1}(\frac{29.11}{24.23}) \rangle = \langle 37.87,50.2^{\circ}\rangle[/tex]
Which item stores the least electrical potential energy within their capacitors?
Wrist watch
Tablet
Television
Heating and cooling system
Answer:
wrist watch
Explanation:
The energy stored in a spring of a watch is potential energy which is as a result of winding of the string. This energy is used to run the watch as it converts this potential energy to rotational kinetic energy.
"Wrist watch" stores the least electrical potential energy within their capacitors. A further explanation is below.
Potential energy has already been collected sometimes in kind of wrist watch springtime as nothing more than a consequence of certain string or threading becoming coiled or wrapped around at the item.That very similar energy drives the wrist watch by transforming potential energy into rotational kinetic energies.Thus the response above is appropriate.
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Need help with science questions!
Which best describes how the law of conservation of energy is obeyed in this closed physical system?
A.
The final mechanical energy of the system is the difference between the original mechanical energy of the system and the change in mechanical energy of the system (ΔE). When the piston does work (W), only the mechanical energy added to the system (Q) is transferred to kinetic energy.
B.
The final thermal energy of the system is the sum of the original internal energy of the system and the change in energy of the system (ΔE). When the piston does work (W), all the thermal energy is transferred to kinetic energy.
C.
The final mechanical energy of the system is the sum of the original internal energy of the system and the change in energy of the system (ΔE). When the piston does work (W), all the mechanical energy is transferred to kinetic energy.
D.
The final thermal energy of the system is the difference between the original internal energy of the system and the change in energy of the system (ΔE). When the piston does work (W), only the thermal energy added to the system (Q) is transferred to kinetic energy.
Explanation:
B.
The final thermal energy of the system is the sum of the original internal energy of the system and the change in energy of the system (ΔE). When the piston does work (W), all the thermal energy is transferred to kinetic energy.
The law of conservation of energy states that the total energy of a closed system remains constant over time. This includes both mechanical and thermal energies, where mechanical energy is the sum of kinetic and potential energy, and is conserved in the absence of external forces. The first law of thermodynamics encompasses this principle through the statement that the change in internal energy of a system is equal to the heat added to the system plus the work done on it. So the correct option is A.
Explanation:The law of conservation of energy in a closed physical system indicates that the total energy within the system remains constant over time. This concept is articulated in the question which concerns how mechanical and thermal energies are conserved within such a system. To clarify, none of the answer choices directly match the principles of energy conservation as generally understood in physics. However, using the information provided, we can explore the principles relevant to the question.
In a closed system, mechanical energy, which includes both kinetic and potential energy, is conserved unless acted upon by external forces. If a piston does work (W), it may convert some of the system's internal energy to kinetic energy, but the total mechanical energy of the system will not change. This aligns with the principle that during any process, the change in a system's mechanical energy will be equal to the work done on the system minus any heat transfer (Q).
According to the first law of thermodynamics, the change in internal energy of a system (ΔE) is equal to the heat added to the system (Q) plus the work done on the system (W). This statement encompasses the conservation of thermal energy as part of the system's total energy. The energy may shift between mechanical and thermal forms, but the total remains the same.
Therefore, the interpretation of the law of conservation of energy should reflect these ideas, and none of the answer choices provided perfectly do so. The closest is perhaps option A, which mentions the transfer of mechanical energy and the work done by the piston, but the phrasing about energy differences is not accurate.
Why was the Bill of Rights added to the U.S. Constitution?
To declare independence from Britain
To create the three branches of government
To safeguard Americans' rights
To enforce important laws
Answer:
the answer is to safeguard Americans rights took the test
Explanation:
C. To safeguard American's rights
What is the bill of rights in the U.S. constitution?The bill of Rights is the name given to the primary 10 amendments to our constitution. The bill of Rights consists of guarantees of civil liberties and checks on state power; it was introduced in order to convince states to ratify the constitution.
the 3 most important Bill of Rights
The Bill of Rights lists essential rights to be protected
These include the right to life, dignity, and the right to freedom and security.Slavery or forced labour is illegal.People are also guaranteed the right to privacy, freedom of religion, belief and opinion.Learn more about the bill of rights here
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A substance that is easily magnetized is a
Answer:
the correct answer is ferromagnetic.
The substance which can get easily magnetized is a ferromagnetic substance.
Explanation:
The magnetic properties of a substance classifies any substance into two kinds of substances or materials. These are ferromagnetic substances or the paramagnetic substances.
These two have been classified on the basis of being magnetized. Ferromagnetic substances gets easily magnetized whereas the paramagnetic substances do not get magnetize easily.
Examples of ferromagnetic substances: Iron, Cobalt or Nickel.
Define relative density
Hello There!
Relative density is another word for specific gravity. Relative density is comparing the density of one thing to the density of another. Most of the time, you look at the density of water so we look at the density of an object relative to the density of water.
What's the kinetic energy of an object that has a mass of 30 kilograms and moves with a velocity of 20m/s?
Thank you,
Marilyn
Ek = 6KJ.
In physics, the kinetic energy of a body or object is the one that owns due to its movement and is given by the equation [tex]E_{k} = \frac{1}{2} mv^{2}[/tex], where m is the mass of the object in kilograms and v is the velocity in m/s.
An object that it has a mass of 30 kilograms and moves with a velocity of 20m/s, its kinetic energy is given by:
[tex]E_{k} = \frac{1}{2} (30kg)(20m/s)^{2}=6000J=6KJ[/tex]
A temperature of a 50 kg block increases by 15°C when 337,500 J of thermal energy are added to the block.
a. What is the specific heat of the object? show your work with units.
Explanation:
Heat = mass × specific heat × temperature change
q = m C ΔT
Given:
q = 337500 J
m = 50 kg
ΔT = 15°C
Substitute:
337500 J = (50 kg) C (15°C)
C = 450 J/kg/°C
Specific heat is usually recorded in J/g/°C or kJ/kg/°C. Converting:
C = 0.45 J/g/°C = 0.45 kJ/kg/°C
Final answer:
The specific heat of the object is calculated using the formula Q = mcΔT. Upon substituting the values provided into the formula and rearranging it to solve for specific heat (c), we determine that the specific heat of the object is 450 J/kg°C.
Explanation:
To calculate the specific heat of the object, we use the formula:
Q = mcΔT
Where:
Q is the amount of heat added, in joules
m is the mass of the object, in kilograms
c is the specific heat capacity, in J/kg°C
ΔT is the change in temperature, in degrees Celsius (or Kelvin, since the change is the same in both scales)
We are given the following values:
Q = 337,500 J
m = 50 kg
ΔT = 15°C
We rearrange the formula to solve for c:
c = Q / (mΔT)
Plugging in the values:
c = 337,500 J / (50 kg × 15°C)
c = 337,500 J / 750 kg°C
c = 450 J/kg°C
Therefore, the specific heat of the object is 450 J/kg°C.
To be considered a living thing, an organism must be able
produce oxygen.
increase in size.
C. adapt to change.
D. move independently.
Answer:
D. move independently.
Explanation:
To be considered a living thing, an organism must be able to move independently.
Answer:
To be considered a living thing, an organism must be able adapt to change.
The field around a long, straight wire is:
parallel to the wire
radial to the wire
perpendicular to the wire
concentric with the wire
Answer:
Concentric with the wire
Explanation:
The magnetic field around a long, straight current-carrying wire forms concentric lines around the wire itself. The magnitude of the field is given by:
[tex]B=\frac{\mu_0 I}{2\pi r}[/tex]
where
[tex]\mu_0[/tex] is the magnetic permeability
I is the current in the wire
r is the distance from the wire
The direction of the lines of the field can be determined by using the right-hand rule: the thumb of the right hand points in the same direction as the current, and the other fingers (wrapped around the thumb) gives the direction of the field lines.
Answer:
concentric with the wire
Explanation:
Graphs are representations of equations.
A. True
B. False
Answer:
Hi there!
The answer is: A. True
When a wave moves from a dense medium to a less dense medium most of the wave energy is
Answer:when a wave moves from a dense medium to a less dense medium most of the wave energyis refracyed.
Explanation:
Answer: reflected
Explanation: A P E X
Which statement correctly describes the relationship between frequency and wavelength?
As the frequency of a wave increases, the longer its wavelength is.
As the frequency of a wave increases, the shorter its wavelength is.
As the frequency of a wave increases, its wavelength remains the same.
For a wave:
v = fλ
v is the velocity, f is the frequency, and λ is the wavelength.
Assuming the velocity of the wave doesn't change...
If you increase its frequency, its wavelength will shorten.
Answer:
As the frequency of a wave increases, the shorter its wavelength is.
Explanation:
If the mass of an object is 8 kg and its momentum is -80 kgm/s, what is its velocity?
A. 10 m/s
B. 12 m/s
C. 8 m/s
D. -10 m/s
An object's momentum is the product of its mass and its velocity:
p = mv
p is its momentum, m is its mass, and v is its velocity.
Given values:
p = -80kg×m/s
m = 8kg
Plug in these values and solve for v:
-80 = 8v
v = -10m/s
Choice D
The velocity is Option D. -10 m/s
What is velocity?Velocity is the speed at which something moves in the same direction. For example, the speed of a car traveling north on a highway, or the speed a rocket travels after launching.Velocity is defined as the displacement of an object in a unit of time.The formula of velocity isv = p/m
v = velocity
p = momentum
m = mass of the object
An object's momentum exists as the product of its mass and its velocity:
p = mv
p is its momentum, m exists its mass, and v stands for its velocity.
Given values:
p = -80kg×m/s
m = 8kg
Plug in these values and solve for v:
-80 = 8v
v = -10m/s
The SI unit of velocity is m/s.Velocity is also defined as the rate of change of displacement of the body with respect to time.The velocity is Option D. -10 m/s
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A vector quantity is always the same as a scalar quantity.
True or false
Answer:
false
Explanation:
because
scalar quantity :has only magnitude but no direction
vector quantity : has both magnitude and direction
An astronaut in a space craft looks out the window and sees an asteroid move pas a backward direction at 68 mph relative to the space craft. If the velocity of the space craft is 126 mph relative to the position of the sun, what is the velocity of the asteroid relative to the sun?
Answer: -194 mph
Explanation:
Taking into account the Sun as the center (origin, point zero) of the reference system, the velocity of the spacecraft relative to the Sun [tex]V_{R-S}[/tex] is:
[tex]V_{R-S}=126mph[/tex] Note it is positive because the spacecraft is moving away from the Sun
Taking into account the spacecraft as the center of another reference system, the velocity of the asteroid relative to the spacecraft [tex]V_{A-R}[/tex] is:
[tex]V_{A-R}=-68mph[/tex] Note it is negative because the asteroid is moving towards the spacracft.
Now, the velocity of the asteroid relative to the Sun [tex]V_{A-S}[/tex] is:
[tex]V_{A-S}=V_{A-R}-V_{R-S}[/tex]
[tex]V_{A-S}=-68mph-126mph[/tex]
Finally:
[tex]V_{A-S}=-194mph[/tex] This is the velocity of the asteroid relative to the Sun and its negative sign indicates it is moving towards the Sun.
The asteroid's velocity relative to the spacecraft (68 mph) from the spacecraft's velocity relative to the sun (126 mph), resulting in 58 mph.
The question involves calculating the velocity of the asteroid relative to the sun, given its velocity relative to a spacecraft and the spacecraft's velocity relative to the sun. To do this, we need to add the velocities, taking into account the direction each one is moving.
Since the asteroid is moving in the opposite direction to the spacecraft relative to it, we subtract the asteroid's velocity from the spacecraft's velocity. The spacecraft's velocity relative to the sun is 126 mph. Therefore, we subtract the asteroid's relative velocity of 68 mph from this to find the asteroid's velocity relative to the sun.
The asteroid's velocity relative to the sun = spacecraft's velocity relative to the sun - asteroid's velocity relative to the spacecraft = 126 mph - 68 mph = 58 mph.
Thus, the asteroid is moving at 58 mph relative to the sun.
When a person rides a bicycle past a tree while wearing a helmet, the person is moving relative to
only the bicycle
only the tree
the tree and the bicycle
the bicycle, the tree, and the helmet
A person riding a bicycle past a tree while wearing a helmet is moving relative to the tree, the bicycle, and the helmet. This is a concept in physics known as frames of reference, implying movement and direction are dependent on the perspective of observation.
Explanation:When a person rides a bicycle past a tree while wearing a helmet, the person is moving relative to the tree, the bicycle, and the helmet. That is to say, if you were observing from the cyclist's perspective, everything would be moving: the tree as they pass, the bicycle beneath them, and even their helmet.
This is typical of what we discuss in physics as frames of reference, with the notion of relative movement. While the tree appears to move in one direction, the bicycle and helmet in another, everything depends on your perspective or your frame of reference.
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to find power we need to determine?
Answer:
Work and time needed to the work
Explanation:
Power is defined as follows:
[tex]P=\frac{W}{t}[/tex]
where
P is the power
W is the work done
t is the time needed to do the work
Since the work can also be rewritten as the product between force (F) and displacement (d):
W = F d
The power can be also rewritten as
[tex]W=\frac{Fd}{t}[/tex]
But [tex]\frac{d}{t}[/tex] is equal to the velocity, v; so, power can be rewritten as product between force and velocity:
[tex]P=Fv[/tex]
Which of the following is equal to an impulse of 15 units?
A) Force = 10, Time = 0.5
B) Force = 7.5, Time = 2
C) Force = 20, Time = 1.5
D) Force = 15, Time = 1.5
Answer:
B) Force = 7.5, Time = 2 is equal to an impulse of 15 units
It totally depends on WHAT the units are.
IF the force is 7.5 Newtons AND the time is 2 seconds, THEN the impulse is 15 newton-seconds or 15 kg-m/sec. (choice-B)
If either of them isn't, then it isn't.
What is a hypothesis?
a. a report of the findings of scientific experiments
b. use of isolated facts to reach a general idea that may explain a phenomenon
c. a general statement made to infer a specific conclusion, often in an “if. . . then” format.
d. a tentative statement, based on data, that can be used to guide further observations and experiments
Which statement best explains why Earth is not a perfect sphere?
Earth revolves too quickly around the Sun
Earth's spin on its axis causes the equator to bulge
The circumference of the Earth is greater at its poles
The gravity of the moon changes Earth's shape
Answer:
Earth's spin on its axis causes the equator to bulge
Explanation:
The Earth is not a perfect sphere but an oblate ellipsoid. The force that holds a planet is gravity. The Earth is rotating on its axis at a speed of 460 m/s at the equator. Due to this reason there is a build up of centrifugal force on the Earth which causes it to expand giving it a bulge.
The Sun and the Moon's gravity causes waves on the surface of large water bodies.
You have 30.0 L of gasoline. How many gallons is this? (1 L equals about 0.264 gallons).
Answer:7.92 gallons
Explanation:
What is the average acceleration during the time interval 0 seconds to 10 seconds?
O A.
0.5 meters/seconda
B.
1 meter/second?
C.
2 meters/second?
D.
3 meters/seconde
Answer:
A. [tex]0.5 m/s^2[/tex]
Explanation:
The average acceleration is equal to the ratio between the change in velocity and the time elapsed:
[tex]a=\frac{\Delta v}{\Delta t}[/tex]
The change in velocity between t=0 s and t=10 s is the change on the vertical axis:
[tex]\Delta v = 5 -0 = 5 m/s[/tex]
Whule the time interval is
[tex]\Delta t = 10 s[/tex]
So the average acceleration is
[tex]a=\frac{5 m/s}{10 s}=0.5 m/s^2[/tex]
Answer:
A
Explanation:
plato
PLEASE ANSWER FIRST GETS BRAINLIEST
Explain the role electrons play in producing light
Answer:
Electrons jump between energy levels, absorbing and releasing energy as they are jumping between energy levels. The energy given off corresponds to different frequencies of light. If the light is visible, we see these frequencies as different colors.
Electrons play a crucial role in producing light. When an electron gains energy, it moves to a higher energy level and quickly returns to its original level, releasing the excess energy as a photon. The energy of the photon determines its color or wavelength, allowing scientists to manipulate light color and intensity by controlling electron energy levels.
Electrons play a crucial role in producing light. When an electron in an atom gains energy, it moves to a higher energy level or orbital. However, this excited state is unstable, so the electron quickly returns to its original energy level, releasing the excess energy in the form of a photon, which is a particle of light.
The energy of the photon determines its color or wavelength. For example, blue light has a higher energy than red light. By controlling the energy levels of electrons in objects such as light bulbs or LEDs, scientists and engineers can manipulate the color and intensity of light produced.
This phenomenon is seen in fluorescent lights, where electricity is used to excite electrons in a gas, causing them to release photons. These photons then strike a material called a phosphor, which emits visible light. So, without electrons and their ability to gain and release energy, we wouldn't have light as we know it.
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At exactly the same time, Daisy and Damond both step off a diving platform 5 meters high. Damond jumps up and out from the platform, whereas Daisy just just takes a step from a standing position.
Which of the following is true?
A. The person who has less mass will reach the water first.
B. Daisy will reach the water first.
C. Damon will reach the water first.
D. Damond and Daisy will reach the water at the same time.
Answer:
B
Explanation:
A. False. Their mass does not affect when they reach the water.
B. True. Daisy will reach the water in 1 second.
C. False. Damon will reach the water in more than 1 second.
D. False. Daisy reaches the water first.
A ball is launched horizontally at 150 m/s from a cliff. What is its initial vertical velocity? A. 30 m/s B. 50 m/s C. 150 m/s D. 0 m/s
NEED HELP ASAP!!!!!!
Final answer:
The correct answer is D. 0 m/s. This is because the ball has no initial vertical velocity when launched horizontally from a cliff.
Explanation:
The initial vertical velocity for a ball launched horizontally from a cliff would be 0 m/s. This is because when an object is thrown horizontally, it means that all of its initial velocity is in the horizontal direction, and thus it has no initial vertical velocity.
Looking at our options:
A. 30 m/sB. 50 m/sC. 150 m/sD. 0 m/s - Correct Answer.How is the solubility of a solid affected by temperature?
How is the solubility of a solid affected by temperature?
A) As temperature goes up, the solubility goes up.
B) As temperature goes down, the solubility goes down.
C) As temperature goes up, the solubility goes down.
D) As temperature goes down, the solubility goes up.
E) both A and B
Answer:
E
Explanation:
As temperatures go up solids become more towards the next state of matter, liquid which is very soluable (like mixing drinks). while as it gets colder, solids become more solid, the atoms come closer together which forms stronger bonds between them so they don't want to mix as well. Solids, for the most part can only become more solid as it gets colder, unless you count bohrs-einstein conisates
A vessel (see the figure) comprises of into two chambers
X and Y with an adiabatic wall. The adiabatic wall can
move freely. The chambers X and Y contain an ideal gas
under the condition that pressure P, volume V, and
temperature T are all same, respectively. The system
gains an equilibrium fate after heating when the
temperature of chamber X becomes 3T. while the
temperature of chamber Y is always constant at T. The
gas pressure of chamber Y at the equilibrium after the
heating is ....
Answer:
(C) 2P
Explanation:
Ideal gas law states:
PV = nRT
n (the number of moles) and R (ideal gas constant) are constant, so we can say:
(PV / T) before = (PV / T) after
Chamber X starts at pressure P, volume V, and temperature T. At equilibrium, the pressure is Px, the volume is Vx, and temperature 3T.
PV / T = Px Vx / 3T
Chamber Y starts at pressure P, volume V, and temperature T. At equilibrium, the pressure is Py, the volume is Vy, and temperature T.
PV / T = Py Vy / T
Substituting and simplifying:
Px Vx / 3T = Py Vy / T
Px Vx / 3 = Py Vy
Since the chambers are at equilibrium, Px = Py:
Vx / 3 = Vy
Vx = 3 Vy
The total volume is the same as before, so:
Vx + Vy = 2V
Substituting:
(3 Vy) + Vy = 2V
4 Vy = 2V
Vy = V / 2
Now if we substitute into our equation for chamber Y:
PV / T = Py (V/2) / T
PV = Py (V/2)
Py = 2P
The pressure in chamber Y (and chamber X) doubles at equilibrium.
The gas pressure of chamber Y at the equilibrium after the
heating is 2P.
What is Ideal gas law?
This is defined as the equation of state of a hypothetical ideal gas and it is depicted by the following below:
PV = nRT
We can infer that the number of moles(n) and R (ideal gas constant) are constant
PV / T (Initial) = PV / T (Final)
We were told that Chamber X starts at pressure P, volume V, and temperature T. At equilibrium, the pressure is Px, the volume is Vx, and temperature 3T.
PV / T = P V / 3T
We were also told that Chamber Y starts at pressure P, volume V, and temperature T. At equilibrium, the pressure is Py, the volume is Vy, and temperature T.
PV / T = Py Vy / T
Substitute into the equation:
Px Vx / 3T = Py Vy / T
Px Vx / 3 = Py Vy
At equilibrium, the chambers are : Px = Py:
Vx / 3 = Vy
Vx = 3 Vy
The total volume is the same as before, so:
Vx + Vy = 2V
Substitute into the equation
(3 Vy) + Vy = 2V
4 Vy = 2V
Vy = V / 2
Substitute into our equation for chamber Y:
PV / T = Py (V/2) / T
PV = Py (V/2)
Py = 2P
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distinguish between uniform and non uniform motion.Is uniformly accelerated motion uniform motion ?
No.
Uniform motion means no acceleration ... speed and direction are not changing.
Uniform motion involves moving at a constant velocity, while non-uniform motion entails changes in speed or direction. Uniformly accelerated motion changes velocity over time and is not uniform. Uniform circular motion has a constant speed but changes direction, while non-uniform circular motion changes in speed and possibly acceleration.
Explanation:Uniform motion occurs when an object moves at a constant velocity, meaning that it covers equal distances in equal intervals of time regardless of the length of the interval. On the other hand, non-uniform motion involves changes in the speed or direction of the object, meaning the object does not cover equal distances in equal time intervals, which can include speeding up, slowing down, or changing direction.
Uniformly accelerated motion is not considered uniform motion because, even though the acceleration is constant, the velocity of the object changes over time. Specifically, in uniformly accelerated motion, the object’s speed increases or decreases at a steady rate, leading to a change in velocity.
Uniform circular motion refers to an object moving along a circular path with a constant speed, which means that the object’s velocity is constant in magnitude, but changing in direction. This is a special type of uniform motion because it involves constant speed but the direction is continually changing, which implies the presence of acceleration. Conversely, non-uniform circular motion refers to when an object is traveling along a circular path but with a changing speed, which can also mean changing acceleration.
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Superposition of two wave crests produces ____ interference.
Constructive
Destructive
Answer:
Constructive
Explanation:
Superposition of two wave crests produces constructive interference.
Answer:
Superposition of two wave crests produces destructive interference.
Explanation:
You may have already let your phone ring near the speakers of a computer and noticed that they started to sizzle. You must also have heard that, when traveling by plane, the cell phone must be turned off to avoid failures in the communication devices. Both cases have the same reason: wave interference. Waves are energetic pulses that propagate through space periodically. When two waves overlap in the same region of space, interference occurs, which results in another wave with different intensity. These inferences can be either constructive or destructive.
The superposition of two wave crests produces destructive interference. This type of inference occurs when two waves that meet have different phases, so that one annihilates the other. The result is a wave with zero amplitude.