Answer:
blanket= texture, thermal conductivity,and mass
glass= the rest
Explanation:
im not good at explaining
A pole-vaulter is nearly motionless as he clears the bar, set 4.2 mm above the ground. He then falls onto a thick pad. The top of the pad is 80 cmcm above the ground, and it compresses by 50 cmcm as he comes to rest.
Required:
What is his acceleration as he comes to rest on the pad?
Answer:
-67.24 m/s²
Explanation:
From the given information:
Using the formula for Kinematic equation i,e [tex]v_y^2 -v_{0y}^2=2a_yd[/tex] to find the speed with which the pole-vaulter approaches the pad
where;
[tex]v_y =[/tex] the speed when the individual approaches the pad = ???
[tex]v_{oy}=[/tex] initial speed at the location of the bar = 0
[tex]a_y =[/tex] the individual acceleration which is also equivalent to acceleration due to gravity. = 9.8 m/s²
d = distance travelled
Thus;
d = 4.2m - 80 cm
d = 4.2 m - 0.8 m
d = 3.4 m
[tex]v_y^2 -(0)^2=2\times 9.8 \ m/s^2 \times 3.4 \ m[/tex]
[tex]v_y^2 =2\times 9.8 \ m/s^2 \times 3.4 \ m \\ \\ v_y ^2 = 66.64 \ m/s \\ \\ v_y = \sqrt{66.64 \ m/s} \\ \\ v_y = 8.2 \ m/s[/tex]
Thus, the initial speed of the pole-vaulter at the top of the pad = 8.2 m/s
Using the same above equation to determine the acceleration as the pole-vaulter approaches rest on the pad:
i.e
[tex]v_f^2 -v_{0}^2=2a_yd'[/tex]
[tex]0^2 -(-8.2\ m/s)^2=2a(0.5 \ m) \\ \\ a = - \dfrac{(8.2 \ m/s)^2}{2(0.5 \ m) } \\ \\ \mathbf{a = -67.24 \ m/s^2}[/tex]
A waterfall is an example of what energy conversion?
Answer:
most common energy transformations is the transformation between potential energy and kinetic energy. In waterfalls such as Niagara Falls, potential energy is transformed to kinetic energy. The water at the top of the falls has gravitational potential energy. As the water plunges, its velocity increases.
Explanation:
Hope this helps you
( I got this from transformation and conservation article)
The plane has just taken off and reached a height of 200 m when one of its wheels falls off.
The wheel has a mass of 300 kg.
What speed does it hit the ground with?
(Ignore air resistance.)
Give your answer to the nearest 0.1 m/s
Use g = 9.8 m/s2 for the acceleration due to gravity.
A
6.3 m/s
Answer: 63 m/s
Explanation: If wheel drops vertically, you can use
conservation of energy : Ep = Ek. mgh = ½mv^2 and
solve v = √(2gh ) = √ (2·9.81 m/s²·200 m) = 62.6 m/s.
NOTE: wheel has also horizontal speed which was not mentioned here.
HELP ASAP DUE IN 5MIN
1. When a skydiver jumps out of a plane, the force that converts PE to KE is ?
2. In a fair experiment, the things that can change, causing a change in the outcome are called?
3. For a test to produce strong evidence for a claim, how many variables must be tested at a time?
At a playground a student runs at a speed of 5 m/s and jump onto a circular disk of radius 3/2 m that is free to rotate around a fixed vertical axle. The student jumps on the disk several times, and the angular speed after the student lands is measured each time. Which of the following angular speeds is not a reasonable value for the measured angular speed?
a. 0.5 rad/s
b. 1 rad/s
c. 2 rad/s
d. 3 rad/s
e. 4 rad/s
Answer:
e. 4 rad/s
Explanation:
The maximum amount of angular velocity that can be reached by the disk can be found using the following formula:
[tex]v = r\omega\\\\\omega = \frac{v}{r}[/tex]
where,
ω = maximum angular velocity = ?
v = linear speed = 5 m/s
r = radius of disc = 1.5 m
Therefore,
[tex]\omega = \frac{5\ m/s}{1.5\ m} \\\\\omega = 3.33\ rad/s[/tex]
Therefore, the angular speed can be lower than this value due to frictional losses, but it can not exceed this value in the given linear speed limit of 5 m/s.
Hence, the correct option is:
e. 4 rad/s
A thin film of acetone (n=1.25) lies on the surface of a thick piece of water (n=1.30). White light shines down from air onto the thin layer of acetone. Destructive interference occurs for m=3 for a wavelength in air of 600 nm. What is the thickness of the thin film?
Answer:
Explanation:
The wave of light is being reflected two times while going from lower to higher refractive index mediums
So there will be phase reversal two times .
Condition of destructive index
2 μ t = ( 2m+1) λ / 2
Substituting the values
2 x 1.25 x t = ( 2 x 3 + 1 ) x 600nm / 2
2.5 t = 2100 nm
t = 840 nm .
which chareged particles contribute to electricity, magnetism, and light
Answer:
Explanation:charged particles create an electric force field. Moving charged particles create a magnetic force field. Accelerating charged particles produce changing electric and magnetic force fields which propagate as EM waves.
(1) Viewers of Star Trek hear of an antimatter drive on the Starship Enterprise. One possibility for such a futuristic energy source is to store antimatter charged particles in a vacuum chamber, circulating in a magnetic field, and then extract them as needed. Antimatter annihilates with normal matter, producing pure energy. What strength magnetic field is needed to hold antiprotons, moving at 5.0 x 10^7 m/s in a circular path 2.00 m in radius? Antiprotons have the same mass as protons but the opposite (negative) charge.
(2) Is this field strength obtainable with today’s technology or is it a futuristic possibility?
Solution :
The relationship between the strength of magnetic field and the radiusof a charged particle's path is obtained through Newton's second law, which is given by :
F = ma
F = qvB and [tex]$a=\frac{v^2}{r}$[/tex]
Substituting these values in the second law of Newton,
[tex]$qvB=\frac{mv^2}{r}$[/tex]
Now solving for B, we get:
[tex]$B = \frac{mv}{rq}$[/tex]
[tex]$=\frac{(1.67 \times 10^{-27})(5 \times 10^{7})}{2\times 1.6 \times 10^{-19}}$[/tex]
= 0.261 T
The field strength can be obtained by using the technology of today.
what is the acceleration of each body of mass 5kg rests on a frictionless table and is connected to a cable that passes over a pulley onto a hanging body of mass 10kg
Answer:
6.53 m/s²
Explanation:
Let m₁ = 5 kg and m₂ = 10 kg. The figure is attached and free body diagrams of the objects are also attached.
Both objects (m₁ and m₂) have the same magnitude of acceleration(a). Let g be the acceleration due to gravity = 9.8 m/s². Hence:
T = m₁a (1)
m₂g - T = m₂a (2)
substituting T = m₁a in equation 2:
m₂g - m₁a = m₂a
m₂a + m₁a = m₂g
a(m₁ + m₂) = m₂g
a = m₂g / (m₁ + m₂)
a = (10 kg * 9.8 m/s²) / (10 kg + 5 kg) = 6.53 m/s²
Both objects have an acceleration of 6.53 m/s²
Lupus is a temporary disease that can be cured easily. True False
Answer:
falseeee
Explanation:
PLEASE HELP ASAP!!!!!
How much heat is required to heat 2 kg of water from 25°C to 40°C?
Answer:
126000 J
Explanation:
Applying,
Q = cm(t₂-t₁).................. Equation 1
Where Q = Amount of heat, c = specifc heat capacity of water, m = mass of water, t₁ = Initial temperature, t₂ = Final temperature.
From the question,
Given: m = 2 kg, t₁ = 25°C, t₂ = 40°C
Constant: c = 4200 J/kg.°C
Substitute these value into equation 1
Q = 2×4200(40-25)
Q = 2×4200×15
Q = 126000 J
what is Archimedes principle?
Archimedes' principle states that a body immersed in a fluid is subjected to an upwards force equal to the weight of the displaced fluid. This is a first condition of equilibrium. We consider that the above force, called force of buoyancy, is located in the centre of the submerged hull that we call centre of buoyancy.
When the velocity of a body increase with time, it's acceleration is ---------
positive
negative
Answer:
Negative
Explanation:
A 190 lb man riding a 30 lb bicycle rides up a hill 60 ft high in one minute. What is the horsepower developed during this time?
With no friction, you can use the relationship between potential and kinetic energy to predict the speed of the car at the bottom of this hill from its starting height.
a. True
b. False
The bob (weight) at the end of a pendulum has a mass of 0.3 kilograms. The bob is pulled to position B and allowed to swing. It goes all the way to position C and swings
back.
joules. If the maximum height of the bob is 0.45 meters when it swings back,
joules of energy was
The potential energy of the bob at position B is
transformed to thermal energy.
Use g = 9.8 m/s2 and PE = mxgxn.
Answer: The first box is 1.47
The second box is 1.323
Explanation:
The potential energy of the pendulum bob at position B is 1.323 J.
What is the potential energy of the box of the pendulum?Potential energy is the energy a body has by virtue of its position or state above the ground.
Potential energy = mass × acceleration due to gravity × heightThe mass of the bob = 0.3 kg
height above the ground = 0.45 m
acceleration due to gravity, g = 9.8 m/s^2
Potential energy = 0.3 × 0.45 × 9.8 = 1.323 J
Therefore, the potential energy of the pendulum bob at position B is 1.323 J.
Learn more about potential energy at: https://brainly.com/question/14427111
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POSSIBLE POINTS: 4
A sound wave traveling through a solid material has a frequency of 5 hertz. The wavelength of the sound wave is 2 meters. What is the speed of sound in
the material?
50 m/s
1,000 m/s
.
25 m/s
10 m/s
17
18 19 20 21 22 23 24 25 26
19 20 21 2
Ne
12631
MAY
20
0
étv
Answer:
v = fy
speed is equal to frequency × wavelength
5 × 2
[tex]10m.s^{ - 1} [/tex]
Explain the difference between the speed of an Electromagnetic wave and its frequency?
Answer:
Electromagnetic waves differ in their wavelengths and frequencies. The higher the frequency of an electromagnetic wave, the greater its energy. The speed of an electromagnetic wave is the product of its wavelength and frequency, so a wave with a shorter wavelength has a higher frequency, and vice versa.
Explanation:
The block slides on a horizontal frictionless surface. The block has a mass of 1.0kg and is pushed 5.0N at 45°. What is the magnitude of the acceleration of the block?
Answer:
[tex]3.5\:\mathrm{m/s^2}[/tex]
Explanation:
Newton's 2nd law is given as [tex]\Sigma F = ma[/tex].
To find the acceleration in the horizontal direction, you need the horizontal component of the force being applied.
Using trigonometry to find the horizontal component of the force:
[tex]\cos 45^{\circ}=\frac{x}{5},\\\frac{\sqrt{2}}{{2}}=\frac{x}{5},\\x=\frac{5\sqrt{2}}{2}[/tex]
Use this horizontal component of the force to solve for for the acceleration of the object:
[tex]\frac{5\sqrt{2}}{2}=1.0\cdot a,\\a=\frac{5\sqrt{2}}{2}\approx \boxed{3.5\:\mathrm{m/s^2}}[/tex]
Think about routine tasks that astronauts might need to do inside and outside a
spaceship. Choose several tasks, and describe the features the ship and spacesuits
should have to account for zero gravity as the astronaut completes the task. Use
Newton's laws of motion in your analysis..
from the NASA website, COPYRIGHT Jun 8, 2015
A Thomson's gazelle can run at very high speeds, but its acceleration is relatively modest. A reasonable model for the sprint of a gazelle assumes an acceleration of 4.2m/s2 for 6.5s , after which the gazelle CONTINUES at a steady speed.
a. What is the gazelles top speed?
b. A human would win a very short race with a gazelle. The best time for a 30 m sprint for a human runner is 3.6 s. How much time would the gazelle take for a 30 m race?
Answer:
The correct answer will be:
(a) 27.3 m/s
(b) 3.8 s
Explanation:
According to the question:
Acceleration,
[tex]a= 4.2 \ m/s^2[/tex]
Time,
[tex]t = 6.5 \ s[/tex]
(a)
The gazelles top speed will be:
⇒ [tex]V_{max} = at[/tex]
[tex]=4.2\times 6.5[/tex]
[tex]=27.3 \ m/s[/tex]
or,
[tex]= 27 \ m/s[/tex]
(b)
As we know,
s = 30 m
Now,
⇒ [tex]s = \frac{1}{2} at^2[/tex]
or,
⇒ [tex]t=\sqrt{\frac{2s}{a} }[/tex]
On putting the given values, we get
[tex]=\sqrt{\frac{2\times 30}{4.2} }[/tex]
[tex]=\sqrt{\frac{60}{4.2} }[/tex]
[tex]=3.78 \ s[/tex]
or,
[tex]=3.8 \ s[/tex]
what are the advantages of having a roof with a lower thermal conductivity?
Which of the following two is correct
Less energy is needed to heat the house
The roof is a better insulator
The roof is less likely to leak
The rate of energy transfer by conduction is greater
Weather will have a greater effect on the temperature of the house
Answer:
less energy is needed to heat the house
the roof is a better insulator
The correct advantage of having a roof with a lower thermal conductivity is Less energy is needed to heat the house. The correct answer is option 1.
A roof with lower thermal conductivity acts as a better insulator, reducing heat transfer between the interior and exterior of the house. This means that during colder months, less heat escapes through the roof, requiring less energy to maintain a comfortable temperature indoors. Additionally, a roof with lower thermal conductivity will help regulate indoor temperatures more effectively, making it a better insulator against external weather conditions. It does not directly affect the likelihood of roof leaks or increase the rate of energy transfer by conduction. Option 1 is correct.
To know more about thermal conductivity, here
brainly.com/question/14553214
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--The complete Question is, What are the advantages of having a roof with a lower thermal conductivity?
Which of the following two is correct
1. Less energy is needed to heat the house
2. The roof is a better insulator
3. The roof is less likely to leak
4. The rate of energy transfer by conduction is greater
5. Weather will have a greater effect on the temperature of the house. --
If you make multiple measurements of your height, you are likely to find that the results vary by nearly half an inch in either direction due to measurement error and actual variations in height. You are slightly shorter in the evening, after gravity has compressed and reshaped your spine over the course of a day. One measurement of a man's height is 6 feet and 1 inch. Express his height in meters, using the appropriate number of significant figures.
Answer:
H = 1.85 m
Explanation:
First, we will convert the height completely into inches. 1 feet contains 12 inches in it. Therefore:
H = (6 feet)(12 inch/1 feet) + 1 inch
H = 73 inches
Now, we will convert this height from inches to meters. 1 inch is equivalent to 0.0254 m. Therefore:
H = (73 inches)(0.0254 m/1 inch)
H = 1.85 m
Electromagnetic waves transport energy. This problem shows you which parts of the energy are stored in the electric and magnetic fields, respectively, and also makes a useful connection between the energy density of a plane electromagnetic wave and the Poynting vector. In this problem, we explore the properties of a plane electromagnetic wave traveling at the speed of light calong the x axis through vacuum. Its electric and magnetic field vectors are as follows:
E= EoSin(kx- ωt)j
B= BoSin (kx- ωt)k
Throughout, use these variables (E, B, Eo, Bo, k, x, and w) in your answers. You will also need the permittivity of free space εo and the permeability of free space μo.
Required:
What is the instantaneous energy μE(t) in the electric field of the wave?
Answer:
S = (√(ε₀/μ₀)(Eo²Sin²(kx- ωt)i
Explanation:
The instantaneous energy of the wave is given by the Poynting vector, S = 1/μ₀(E × B) where μ₀ = permeability of free space
So, substituting the variables into the equation with E= EoSin(kx- ωt)j and B= BoSin (kx- ωt)k
So, S = 1/μ₀(E × B)
S = 1/μ₀(EoSin(kx- ωt)j × BoSin (kx- ωt)k)
S = 1/μ₀(EoSin(kx- ωt) × BoSin (kx- ωt) (j × k)
S = 1/μ₀(EoBoSin²(kx- ωt)i (i = j × k)
Now,
Eo/Bo = c where c = speed of light
So, Bo = Eo/c
Thus
S = 1/μ₀(EoBoSin²(kx- ωt)i
S = 1/μ₀(Eo(Eo/c)Sin²(kx- ωt)i
S = 1/cμ₀(Eo²Sin²(kx- ωt)i
Also,c = 1/√μ₀ε₀ where ε₀ =permittivity of free space
So,
S = 1/cμ₀(Eo²Sin²(kx- ωt)i
S = 1/(1/√μ₀ε₀)μ₀(Eo²Sin²(kx- ωt)i
S = 1/(1/√(ε₀/μ₀)(Eo²Sin²(kx- ωt)i
S = (√(ε₀/μ₀)(Eo²Sin²(kx- ωt)i
which is the instantaneous energy in the electric field.
True or False: It would be easier to run on a planet with high gravity than one with less gravity.
Use the worked example above to help you solve this problem. The half-life of the radioactive nucleus _(88)^(226)text(Ra) is 1.6 103 yr. If a sample initially contains 4.00 1016 such nuclei, determine the following:________.
(a) the initial activity in curies µCi
(b) the number of radium nuclei remaining after 4.4 103 yr nuclei
(c) the activity at this later time µCi
Answer:
Explanation:
From the information given:
The half-life [tex]t_{1/2}[/tex] = 1.6103 years
The no. of the initial nuclei [tex]N_o[/tex] = [tex]4.00 \times 10^6[/tex]
Using the formula:
[tex]N = N_o exp(-\lambda t)[/tex]
where;
decay constant [tex]\lambda = \dfrac{In2}{1.6*10^3} y^{-1}[/tex]
∴
[tex]N = N_o exp ( \dfrac{-In2}{1.6*10^3}\times 4.4 \times 10^3)[/tex]
[tex]N = N_o exp (- 1.906154747)[/tex]
The number of radium nuclei N = 5.94 × 10¹⁵
The initial activity[tex]A_o = \lambda N_o[/tex]
[tex]A_o =(\dfrac{In (2)}{1.61\times 10^3 \times 365 \times 24 \times 3600}\times 4.00 \times 10^{16})[/tex]
[tex]A_o =546075.8487 \ Bq[/tex]
Since;
1 curie = 3.7 × 10¹⁰ Bq
Then;
[tex]A_o =\dfrac{546075.8487 }{3.7\times 10^{10}}[/tex]
[tex]A_o = 1.47588 \times 10^{-5}Ci[/tex]
[tex]A_o = 14.7588 \ \mu Ci[/tex]
c) The activity at a later time is:
[tex]=5.94 \times 10^{15}( \dfrac{In (2)}{1.60 \times 10^3 \times 365\times 24 \times 3600})[/tex]
[tex]= 81599.09018 \ Bq \\ \\ = \dfrac{81599.09018}{3.7\times 10^{10}} \ Ci \\ \\ = 2.20538 \times 10^6 \ Ci \\ \\ = 2.20538 \ \mu Ci[/tex]
To measure the heat capacity of an object, all you usually have to do is put it in thermal contact with another object whose heat capacity you know. As an example, suppose that a chunk of metal is immersed in boiling water (100°C), then is quickly transferred into a Styrofoam cup containing 250 g of water at 20°C. After a minute or so, the temperature of the contents of the cup is 24°C. Assume that during this time no significant energy is transferred between the contents of the cup and the surroundings. The heat capacity of the cup itself is negligible.
What is the heat capacity of this chunk of metal?
Answer:
The answer is "[tex]55.05 \ \frac{J}{K}[/tex]"
Explanation:
Given value:
[tex]Q_m=4.184 \times 10^3 \ J\\T_0=100^{\circ}\\T_1=24^{\circ}[/tex]
Calculating the heat capacity of this chunk of metal:
Using formula:
[tex]C_m=\frac{Q_m}{T_0-T_1}\\[/tex]
[tex]=\frac{4.184 \times 10^3}{100 -24}\\\\=\frac{4.184 \times 10^3}{76}\\\\=55.05 \ \frac{J}{K}[/tex]
It takes 24 hours for _______?
a.Earth to circle the sun one time
b.earth to rotate on its axis one time
c. The sun to circle earth one time
d.the sun to rotate on its axis one time
Answer:
C
Explanation:
Earth rotates once in about 24 hours with respect to the Sun, but once every 23 hours, 56 minutes, and 4 seconds with respect to other, distant, stars. Earth's rotation is slowing slightly with time; thus, a day was shorter in the past. This is due to the tidal effects the Moon has on Earth's rotation.
Answer: the answer is b.
ps: the other answer is wrong, the earth rotates around the sun, and the sun doesn't rotate around the earth.
Explanation:
what is meant by measurementwhat are the three requirements for selecting a unit of a physical quantity
Answer:
Three requirements for selecting a unit are
1. The unit should be reproducible.
2. It should be possible to define the unit without ambiguity.
3. The value of the unit should not change with space and time.