Answer:
This demonstration is often done following a discussion of the ideal gas equation of state, PV=nRT.
We begin by weighing a balloon, then blowing it up and weighing it again. In the photo shown on right, the mass indication increased from 3.4 to 3.5 grams. At this point, it is important to note that the scale measures force, even though it reports a conclusion about mass based on the force measurement.
One assumption made in reaching the conclusion is that the buoyant force on the object being weighed is negligible. In the case of the balloon, this is incorrect. The buoyant force on this balloon is equal to the weight of the air displaced.
Since the volume of air inside the balloon is essentially the same as the volume of air displaced, we should expect that the buoyant force would support the weight of the air inside the balloon: The reported mass should not go up at all, because the force required of the scale should not change.
The increase in reported mass of .1 gram is attributed to the higher density of the air inside the balloon: The tension in the balloon compresses the air inside, as attested by the pressure required to blow the balloon up. Evidently, for this experiment, the pressure inside is greater than atmospheric by about 2%.
In the picture at right, the balloon is being pressed into a pan of liquid nitrogen. (The pan is the styrofoam lid of a small lunch box.) The balloon floats lightly on the liquid nitrogen unless pressed down. Pressing down places more surface area in contact with the cold nitrogen and speeds the demonstration. It is interesting to note the buoyant force by this liquified constituent of air.
The balloon shrinks dramatically, as indicated below. When left in contact with the liquid nitrogen long enough (perhaps 5 minutes) the oxygen inside the balloon liquifies, and then the nitrogen liquefies also. Close observation of the photo at the upper left corner of the pan shows some liquid nitrogen bubbles may forming above the dark spot in the center of the pan. One can also make out a faint line at the upper left corner of the pan which is the liquid nitrogen surface. The balloon still floats, riding rather high on that surface. Evidently, some of the balloon contents remain in the gas phase, making the mass of the balloon less than the mass of the displaced liquid nitrogen.
Next, we take the shrunken balloon and place it back on the scale, as above. In this instance, the reported mass is 8.7 grams, an increase of 5.2 grams.
A look at the figure on the right shows a faint line near the bottom of the cold balloon. Above that line, the balloon contains gas; below the liquid. That line represents the top surface of the liquid air inside the balloon. With this evidence, the easy thing to say would be, "Of course, liquids are heavier than gases," but that would be incorrect. We assert that the amount of air inside the balloon has not changed and that the mass of that air is not dependent on temperature.
If these assertions are true, then the force of gravity on the balloon has not changed. The scale reading is determined by the force which it must exert on the balloon in order to keep it stationary. Evidently, the required force is larger when the balloon is shrunken. The reason is that the buoyant force (upward) has decreased to practically zero, leaving the scale alone to balance the downward force by gravity.
From the data, we can say that the change in the buoyant force is equal to the weight associated with the apparent change in mass. The weight of 5.2 grams is about .052 newtons. The buoyant force is less now because the balloon displaces less air. If we could measure the change in volume of the balloon as DV, then the buoyant force would be (r g DV) upwards, where r is the density of air that was displaced by the balloon, and g is the gravitational field strength, 9.8 Newton/kg.
Note that the .052 newton force is not the weight of the air inside the balloon. Rather, it is the weight of the air that was displaced by the balloon. If we ignore the compression of air inside the balloon, the two numbers are the same. However, the two samples are completely different.
We can estimate the volume of the balloon by assuming that the hand in the photograph is about .1meters across. For purposes of estimation, we say that the volume shrank to almost zero when the balloon was cold so that the change in volume was nearly equal to the original volume. Plugging in numbers gives fair agreement with the book value of 1kg/cubic meter for the density of air.
The value for the density of air is secondary to two main features of this demonstration:
Large changes in temperature produce the large changes in volume that are indicated by the ideal gas equation.
The mass of air in a volume equal to the volume of a balloon can be determined provided that the buoyant force is understood.
when the acceleration of a block in simple harmonic motion on a spring is zero, what other quantity is also zero?
Hi there!
When the acceleration of a block in SHM is 0 m/s², the NET FORCE must equal 0 N.
0 m/s² acceleration is obtained when the spring is at its equilibrium point, meaning that:
∑F = -kx (x = displacement from equilibrium point in meters)
If the block is at the equilibrium point, displacement = 0m, so:
∑F = -k(0) = 0 N
With Newton's Second Law, ∑F = ma. If the net force is 0 N, then there is no acceleration experienced by the block.
Thus, the other quantity that must be 0 is the block's NET FORCE.
You make a bar graph with the following data. What do you plot on the x-axis?
a child has the kinetic energy of 71 j the mass of the child is 27kg show that the velocity of the child at this point is 2.3m/s
Explanation:
kinetic energy of child = 1/2 m v^2
71 j. = 1/2×27kg ×v^2
71×2/27= v^2
142/27 = v^2
5.3. =v^2
v= √5.3
v= 2.3 m/s
a person with a mass of 15 kg is walking downhill at a velocity of 10 ms what is the Walkers momentum
Answer:
[tex]150 kg\cdot m/s[/tex]
Explanation:
Same as if he was walking uphill, or horizontally. Momentum is defined as the product of mass times velocity. [tex]p = mv = 15\cdot 10 = 150 kg\cdot m/s[/tex]
if a car travels 90km/h for 15 minutes it will travel a. bc x 10^d what are the values of a, b, c and d
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1. When shot from the barrel of a pellet gun (50.00 cm long), a 5.000 gram pellet moves
from rest to 400.0 m/s. What force does the gun exert on the pellet?
The force the gun exerts on the pellet at the given acceleration is 80 N.
The given parameters;
mass of the pellet, m = 5 g = 0.005 kglength of the gun, d = 50 cm = 5 mfinal velocity of the pellet, v = 400 m/sThe acceleration of the pellet is calculated as follows;
[tex]v^2 = u^2 + 2as\\\\400^2 = 0 + 2(a) (5)\\\\400^2 = 10a\\\\160000 = 10a\\\\16,000 \ m/s^2 = a[/tex]
The force the gun exerts on the pellet at the given acceleration is calculated as;
[tex]F = ma\\\\F = 0.005 \times 16,000\\\\F = 80 \ N[/tex]
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Please help me don’t send me a link cause I can’t download it
Answer:
C. 0.2 m/s west
Explanation:
Dont ever open the links that bots send you, it is a virus..Trust me, i speak from experience.......
The tail of a comet always points Select one: a. in the direction of the comet's motion. b. away from the Sun and becomes longest and brightest at perihelion. c. toward the Sun and disappears at perihelion. d. away from the Sun and disappears at perihelion. e. toward Earth and never varies.
A car accelerates from 20m/s to 30m/s in 10 sec. Find the cars acceleration using v=u+at
Explanation:
we derive the formula of acceleration using the formula so v - u /t so
30-20/10
so the acceleration is 1 m/s square
Please find attached photograph for your answer.
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A cyclist rides 4.7 km east for 17 minutes. He then heads west for 11 minutes, riding 2.9 km. Finally, he rides east for 13 km, which takes 51 minutes.
What is the final displacement of the cyclist from their starting point?
What is the cyclist’s average velocity?
Answer: Look at Explanation
Explanation:
4.7 east
2.9 west
4.7 - 2.9 = 1.8 to the east
then 13km to the west
-1.8 + 13 = 11.2 to the west left side
what Characteristic of an object is related to both kinetic energy and its potential energy a objects velocity b height c speed d mass
Answer:
I think it's a. Object velocity
Explanation:
.
Answer:
Object mass
Explanation:
I had answered and thats what it is
1kg red-hot iron is put into 1 L of cool water. Explain in detail what will happen to the temperatures of both objects.
The equilibrium temperature of the iron-water mixture will be greater than the initial temperature of the cold water but less than the initial temperature of the hot iron.
According to the principle of conservation of energy, the heat lost by the red-hot iron is equal to heat absorbed by the cold water.
[tex]Q_{I} = Q_{w}\\\\m_IC_I(t_I - T) = m_wC_w (T-t_w)[/tex]
where;
T is the equilibrium temperatureFrom the equation given above, we can conclude that the equilibrium temperature of the iron-water mixture will be greater than the initial temperature of the cold water but less than the initial temperature of the hot iron.
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A large solar farm has 21 700 solar panels and generates 5.0 MW of power.
1.0 MW = 1.0 × 106 W
Calculate the average power each panel produces.
Answer:
answer is
Explanation:
average power each panel produces = 21700/ 5×10^6
4340 ×10^-6
that's mean 4340 micro Watt
Science Questions :)
Answer:
The box will move diagonally down to the right
Julie blows a bubble. At first, the pressure of the gas in the bubble is 4kPa. The bubble floats into the air and expands. When it gets to the top of a tree the bubble has a pressure of 2kPa and a volume of 3.5m³. Assuming a constant temperature, what was the volume in m³ of the bubble when it was first blown? Give your answer to three significant figures.
Answer:
P V = N R T
P1 V1 = P2 V2 assuming N, R, and T remain constant
V1 = (P2 / P1) V2
V1 = (2 kPa / 4 k Pa) 3.5 m3
V1 = 3.5 m^3 / 2 = 1.75 m^3
the electromagnetic waves with the highest frequencies are called
- A block of mass 4m can move without friction on a horizontal table. This block is attached to another block of
mass m by a string that passes over a frictionless pulley. If the masses of the string and the pulley are negligible,
what is the magnitude of the acceleration of the descending block?
The magnitude of the acceleration of the descending block is equal to 1.96 m/s².
What is the tension in the string?Tension can be described as a force acting along the length of a rope or a cable, especially a force that comprises by a flexible medium. Tension can be described as an action-reaction pair of forces acting at each end of the length of the medium. Each endpoint carried tension and force from the weight attached.
Given that the block with mass, M₁ = 4m is placed on the horizontal table.
The block with mass, M₂ = m is attached by a string.
The block (M₂) suspended by the string experiences tension (T) in the upward direction and weight in the downward direction.
M₂g - T = M₂a ..............(1)
The block (M₁) placed on the table experienced only one force which is tension (T)
T = M₁ a .....................(2)
From equation (1) and (2):
M₂g - M₁a = M₂a
M₁a + M₂a = M₂g
(M₁ + M₂) a = M₂g
a = M₂g/(M₁ + M₂)
Substitute the value of masses of the blocks:
a = m g /( 4m + m)
a = g/5
a = 1.96 m/s²
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Which is a characteristic of tolerance? A.enjoying your hobbies B.accepting diversity C.having pride in your cultureD. knowing many types of people
Answer:
B
Explanation:
Because Tolerance Is The Level Of Ability That Someone Has To Recognise And Help Others Values And Differences.
Potassium chlorate gives Potassium chloride+Oxygen
Find the Balancing Chemical Equation for the above
Answer:
The balanced equation is given as: $ 2KCl{O_3} \to 2KCl + 3{O_2} $.A young woman walks up 55 steps to the top of a water slide. She slides
down, feet first, all the way to the bottom gaining speed as she goes. If each
step of the slide is.10m tall, how fast will she be going at the bottom?
Answer:
potential energy PE = M g h
KE at bottom = 1/2 M V^2
Regardless of the slope of the slide the change in energy is the same
1/2 V^2 = g h
V = (2 g h)^1/2 = (2 * 9.8 m/s^2 * 10 m)^1/2 = 14 m / s
Perhaps the question says that h = 55 * .1 = 5.5 m
Then V = (2 * 9.8 * 5.5) = 10.4 m/s
An object has an acceleration of 12.0 m/s/s. If the NetForce was tripled and the mass was doubled, then the new acceleration would be _____ m/s/s
Answer: that would be New acceleration would be 12 m/s²
Explanation:
a car traveled 5,300 km in 1 hour whats the average speed is
Answer:
5300km/h
Explanation:
That's an easy question. You can solve it yourself.
The answer can be found by dividing the Distance traveled by the Time.
Now you can solve all the problem of this rule.
If the mass of the Earth is doubled, how will the moon’s orbit be affected?
What Would Happen to the Orbit of the Moon if it Were Twice as Massive? ... The orbit would not change.
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How do you solve problems involving acceleration
Answer:
Velocity/time =acceleration
Acceleration x time = velocity
Velocity/acceleration=time
during which lunar phase does every solar eclipse occur?
Answer:
It has to be the "New Moon" because that is when the moon is between the sun and the earth.
A lunar eclipse can occur when the earth is between the sun and the moon.
What is the force that counteracts the thrust force for flight?
The force which counteracts the thrust force for the flight is known as the drag force, as it opposes the flow.
What is drag force?Drag is a force that opposes an object's relative motion to a fluid environment in the field of fluid dynamics. It may be among two liquid film (or surfaces) or in between a liquid and a flat wall. The drag force is influenced by velocity, as opposed to other resistive forces like dry contact, which are essentially independent of it.
When a flow is moving at low or high speed, the drag force is equal to the speed for low pressure and to the square of the velocity for high-speed flow. Although viscous friction is what ultimately causes drag, turbulent drag is unaffected by viscosity.
A force in physics is an input that has the power to change an object's motion. A mass-containing object's velocity can vary, or accelerate, as a result of a force. Intuitively, a push or a pull can also be used to describe forces.
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The drag force, which resists the flow, is the force that balances the propulsion force for flight.
What is Drag force?In the study of fluid dynamics, drag is a force that opposes an object's relative motion to a fluid environment. It could be situated between two liquid surfaces (or films) or between a liquid and a flat wall.
Unlike other resistive forces like dry contact, which are largely independent of velocity, the drag force is affected by it.
For low pressure and high speed flows, respectively, the drag force is equal to the speed for low pressure and the square of the velocity. Although drag is ultimately caused by viscous friction, turbulent.
Thus, The drag force, which resists the flow, is the force that balances the propulsion force for flight.
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unlike other kinds or muscle cells, ____muscle cells are able to contract by themselves
A. epithelial
B. Liver
C. Intestinal
D. cardiac
Answer:
cardiac
Explanation:
cardiac muscle can contact themselves
what is rotational dynamics
Rotational dynamics is the study of forces and motions about an axis of rotation.
Explanation:Formulas such as Kinematic Equations and Newton's laws can be expressed in rotating coordinate frames such as: Newton's 2nd Law Fnet=m x a translates into Torque = I x α Where I is Moment of Inertia (the rotational analogous term to mass)
Answer:
Rotational dynamics is the study of forces and motions about an axis of rotation.
Explanation:
Formulas such as Kinematic Equations and Newton's laws can be expressed in rotating coordinate frames such as:
Newton's 2nd Law Fnet=m x a translates into Torque =I x α Where I is Moment of Inertia (the rotational analogous term to mass)
and α is angular acceleration.
How is the resultant displacement affected when two displacement vectors are added in a different order
Answer: it is not affected what so ever.
Explanation It will still produce the same resultant.
If a piece of glass permits light to pass through, then it is considered ___________. A. Transparent c. Transmitting b. Reflective d. Absorbent Please select the best answer from the choices provided A B C D.
Answer:
not sure, but I thinks it's either Transparent or Reflective
According to the concept of reflection, if a piece of glass permits light to pass through, then it is considered to be reflective.
What is reflection?Reflection of light is defined as a property of light ray that when it strikes a smooth surface it bounces back .Objects can be seen due to this property of light.Reflection is produced by all types of waves namely sound waves, light waves, electromagnetic waves.
Reflection of light is governed by laws of reflection which are also called as Snell's laws. According to laws of reflection, angle of incidence and angle of reflection are equal.The incident ray , reflected ray and normal all lie on the same side of the plane.Light travels in a straight line before, after and during the process of reflection.There are 3 types of reflection which are diffuse reflection,specular reflection and glossy reflection.
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