Answer: Final temperature is 34.15°C.
Explanation: When two objects have different temperature, they will exchange heat energy until there is no more net energy transfer between them. At that state, the objects are in thermal equilibrium.
So, when in equilibrium, the total heat flow must be zero, i.e.:
[tex]Q_{1}+Q_{2}=0[/tex]
In our case, there will be a change in state of ice into water, so total heat flow will be:
[tex]m_{1}c_{1}(T_{f}-T_{i})+m_{2}c_{2}(T_{f}-T_{i})+mL=0[/tex]
where
m₁ is mass of ice
m₂ is mass of water
c₁ is specific heat of ice
c₂ is specific heat of water
[tex]T_{f}[/tex] is final temperature
[tex]T_{i}[/tex] is initial temperature
L is latent heat fusion
Temperature is in Kelvin so the transformation from Celsius to Kelvin:
For ice:
T = -15 + 273 = 258K
For water:
T = 48 + 273 = 321K
Solving:
[tex]21(2.09)(T_{f}-258)+158(4.186)(T_{f}-321)+21(333)=0[/tex]
[tex]43.89T_{f}-11323.62+661.4T_{f}-212305.55+6993=0[/tex]
[tex]705.3T_{f}=216636.17[/tex]
[tex]T_{f}=[/tex] 307.15K
In Celsius:
[tex]T_{f}=[/tex] 34.15°C
Final temperature of the system when in equilibrium is 34.15°C
Galaxy B moves away from galaxy A at 0.577 times the speed of light. Galaxy C moves away from galaxy B in the same direction at 0.731 times the speed of light. How fast does galaxy C recede from galaxy A?
Answer:
The value is [tex]p = 0.7556 c[/tex]
Explanation:
From the question we are told that
The speed at which galaxy B moves away from galaxy A is [tex]v = 0.577c[/tex]
Here c is the speed of light with value [tex]c = 3.0 *10^{8} \ m/s[/tex]
The speed at which galaxy C moves away from galaxy B is [tex]u = 0.731 c[/tex]
Generally from the equation of relative speed we have that
[tex]u = \frac{p - v}{ 1 - \frac{ p * v}{c^2} }[/tex]
Here p is the velocity at which galaxy C recede from galaxy A so
[tex]0.731c = \frac{p - 0.577c }{ 1 - \frac{ p * 0.577c}{c^2} }[/tex]
=> [tex]0.731c [1 - \frac{ p * 0.577}{c}] = p - 0.577c[/tex]
=> [tex]0.731c - 0.4218 p = p - 0.577c[/tex]
=> [tex]0.731c + 0.577c = p + 0.4218 p[/tex]
=> [tex]1.308 c = 1.731 p[/tex]
=> [tex]p = 0.7556 c[/tex]
name the force that help us to walk
If you lie on the ground at night with no cover, you get cold rather quickly. Much of this is due to energy loss by radiation. At night in a dry climate, the temperature of the sky can drop to −40∘C. If you are lying on the ground with thin clothing that provides little insulation, the surface temperature of your skin and clothes will be about 30∘C. Estimate the net rate at which you body loses energy by radiation to the night sky under these conditions. Hint: What area should we use?
Answer:
301.48 J/s
Explanation:
We are given;
Temperature of the sky dropping to −40∘C: T_o = -40°C = -40 + 273 = 233 K
Temperature of your skin and clothes: T = 30°C = 30 + 273 = 303 K
Body surface area of human body is around 2 m². But here only half of the body is facing the sky, Thus Area is: A = 2/2 = 1 m²
To solve this, we will use the equation for thermal heat transfer known as the Stefan bolt Mann equation.
ΔQ/Δt = εσA(T⁴ - (T_o)⁴)
Where;
ΔQ/Δt is the rate at which you body loses energy by radiation
ε is the emissivity of the human body with a value of 0.97
σ is Stefan boltzmann constant with a value of 5.67 X 10^(-8) W/m².K⁴
Thus;
ΔQ/Δt = 0.97 × 5.67 X 10^(-8) × 1(303⁴ - 233⁴)
ΔQ/Δt = 301.48 J/s
A person standing a certain distance from four identical loudspeakers is hearing a sound level intensity of 125 dB. What sound level intensity would this person hear if all but one are turned off?
Answer:
[tex]\mathbf{\beta = 123.75 \ dB}[/tex]
Explanation:
From the question, using the expression:
[tex]125 \ dB = 10 \ log (\dfrac{I}{I_o})[/tex]
where;
[tex]I_o = 10^{-12} \ W/m^2[/tex]
[tex]I = 10^{12.5} \times 10^{-12} \ W/m^2[/tex]
[tex]I = 3.162 \ W/m^2[/tex]
This is a combined intensity of 4 speakers.
Thus, the intensity of 3 speakers = [tex]\dfrac{3.162\times 3}{4}[/tex]
= 2.372 W/m²
Thus;
[tex]\beta = 10 \ log ( \dfrac{2.372}{10^{-12}} ) \ W/m^2[/tex]
[tex]\mathbf{\beta = 123.75 \ dB}[/tex]
According to the law of conservation of momentum, in an isolated system:
A. The initial and final velocities remain the same.
B. The total initial momentum is equal to the total final momentum.
C. One of the colliding objects must be at rest.
D. The final momentum is always less than the initial momentum.
Answer:
Explanation:B
A 12 kg coyote runs towards a rabbit in the Ortega Mountains
with a velocity of 8 m/s. Determine the momentum of the
coyote.
What is "given" in the word problem?
A) mass and velocity
B) momentum
C) momentum and mass
D) momentum and velocity
Given :
A 12 kg coyote runs towards a rabbit in the Ortega Mountains with a velocity of 8 m/s.
To Find :
The momentum of the coyote.
Solution :
The given in the question is mass of coyote which is 12 kg and velocity which is 8 m/s .
Momentum is given by :
M = mass × velocity
M = 12 × 8 kg m/s
M = 96 kg m/s
Hence, this is the required solution.
What is the atomic number for the following Bohr model?
e
P= 8
N= 8
---
a
8
b
2
OOOO
с
6
d
16
Answer:
8
Explanation:
Atomic number in the Bohr model given is 8.
For every atom, the atomic number is the number of protons in such an atom.
The protons are the positively charged particles found in an atom. They are called the atomic number.
Protons are found in the nucleus of an atom. Together with neutrons, the occupy the tiny nucleus of the atom. By so doing and coupled with their mass, the form the mass of atom. The atomic number is used to identify every atom.A circuit component that is a composed of a semiconductor layer sandwiched between two other semiconductor layers is a(n)?
Explanation:
It's a transistor. Hope that helps!
Answer:
D. Transistor
Explanation:
Edge 2021
The mass and coordinates of three objects are given below: m1 = 6.0 kg at (0.0, 0.0) m, m2 = 1.5 kg at (0.0, 4.1) m, and m3 = 4.0 kg at (1.9, 0.0) m. Determine where we should place a fourth object with a mass m4 = 7.9 kg so that the center of gravity of the four-object arrangement will be at (0.0, 0.0) m
Answer:
The location of the center of gravity of the fourth mass is [tex]\vec r_{4} = (-0.961\,m,-0.779\,m)[/tex].
Explanation:
Vectorially speaking, the center of gravity with respect to origin ([tex]\vec r_{cg}[/tex]), measured in meters, is defined by the following formula:
[tex]\vec r_{cg} = \frac{m_{1}\cdot \vec r_{1}+m_{2}\cdot \vec r_{2}+m_{3}\cdot \vec r_{3}+m_{4}\cdot \vec r_{4}}{m_{1}+m_{2}+m_{3}+m_{4}}[/tex] (1)
Where:
[tex]m_{1}[/tex], [tex]m_{2}[/tex], [tex]m_{3}[/tex], [tex]m_{4}[/tex] - Masses of the objects, measured in kilograms.
[tex]\vec r_{1}[/tex], [tex]\vec r_{2}[/tex], [tex]\vec r_{3}[/tex], [tex]\vec r_{4}[/tex] - Location of the center of mass of each object with respect to origin, measured in meters.
If we know that [tex]\vec r_{cg} = (0,0)\,[m][/tex], [tex]\vec r_{1} = (0,0)\,[m][/tex], [tex]\vec r_{2} = (0, 4.1)\,[m][/tex], [tex]\vec r_{3} = (1.9,0.0)\,[m][/tex], [tex]m_{1} = 6\,kg[/tex], [tex]m_{2} = 1.5\,kg[/tex], [tex]m_{3} = 4\,kg[/tex] and [tex]m_{4} = 7.9\,kg[/tex], then the equation is reduced into this:
[tex](0,0) = \frac{(6\,kg)\cdot (0,0)\,[m]+(1.5\,kg)\cdot (0,4.1)\,[m]+(4.0\,kg)\cdot (1.9,0)\,[m]+(7.9\,kg)\cdot \vec r_{4}}{6\,kg+1.5\,kg+4\,kg+7.9\,kg}[/tex]
[tex](6\,kg)\cdot (0,0)\,[m]+(1.5\,kg)\cdot (0,4.1)\,[m]+(4\,kg)\cdot (1.9,0)\,[m]+(7.9\,kg)\cdot \vec r_{4} = (0,0)\,[kg\cdot m][/tex]
[tex](7.9\,kg)\cdot \vec r_{4} = -(6\,kg)\cdot (0,0)\,[m]-(1.5\,kg)\cdot (0,4.1)\,[m]-(4\,kg)\cdot (1.9,0)\,[m][/tex]
[tex]\vec r_{4} = -0.759\cdot (0,0)\,[m]-0.190\cdot (0,4.1)\,[m]-0.506\cdot (1.9,0)\,[m][/tex]
[tex]\vec r_{4} = (0, 0)\,[m] -(0, 0.779)\,[m]-(0.961,0)\,[m][/tex]
[tex]\vec r_{4} = (-0.961\,m,-0.779\,m)[/tex]
The location of the center of gravity of the fourth mass is [tex]\vec r_{4} = (-0.961\,m,-0.779\,m)[/tex].
How much power is required to carry a 30 N package a vertical distance of 8 m if the work on the package is accomplished in 15 s?
58 W
630 W
21 W
16 W
Answer:
poop bear cookie
Explanation:
How does opening a parachute slow the fall rate of a skydiver?
Answer:
the air is being stopped in the pocket of the parachutes theys why the parachute has a certain shape so that the air that gets caught inside of it as the skydiver goes down slows down the landing
What causes Ep to be converted to Ek? (giving brainliest to right anwser)
Answer:
Energy is a quantity that can be verticality from one to another,
sum of all the energy of the system remains constant if there is no friction force.
Explanation:
The potential energy of a system is a configuration energy, that is, for a given position the energy has a value with respect to a reference point.
Kinetic energy is an energy related to the movement of bodies, that is, a body must have a speed to have kinetic energy.
Energy is a quantity that can be verticality from one to another, the gravitational potential that a body has at a given height when the body is released accelerates by action of gravity, in this case the potential energy decreases and the scientific energy increases, It is appropriate to clarify that the sum of all the energy of the system remains constant if there is no friction force.
When you heat water on a stove, how does its energy change?
A. Its electromagnetic energy decreases.
B. Its thermal energy decreases. c. Its thermal energy increases.
D. Its electromagnetic energy increases.
Answer:
C. its thermal energy increases
Answer:
Explanation:
C
The force of gravity between any two ordinary objects on the earth is.......
A) stronger when closer to the earth
B) stronger if the objects are closer to each other C) always downward
D) stronger than the force of gravity from the earth
Answer:
c
Explanation: beacuse newtons law of phisics says ''what goes up must come down''
The force of gravity between any two ordinary objects on the earth is stronger if the objects are closer to each other.
The force of gravity between two object on the earth surface is given Newton's law of universal gravitation;
[tex]F= \frac{Gm_1m_2}{r^2}[/tex]
where;
G is gravitational constantm₁ and m₂ are the masses of the two objectsr is the distance between the two objectsThe distance between the object is inversely proportional to the force of gravity between the objects. The smaller the distance between the two objects, the greater the force of gravity and vice versa.
Thus, we can conclude that the force of gravity between any two ordinary objects on the earth is stronger if the objects are closer to each other.
Learn more here:https://brainly.com/question/10609143
A cicada produces a sound of roughly 5000 Hz frequency. What category would that sound fall into?
Supersonic
Normal range
Infrasonic
Ultrasonic
A 12 N net force is applied to an object as it moves a distance of 3.0 m: Use the
Work-Kinetic Energy Theorem to determine the object's change in kinetic energy.
Enter your answer in Joules.
Answer:
4 joules
Explanation:
Which two things occur when electric charges move through a conductor?
A. The field is perpendicular to the electron flow.
B. The field is parallel to the electron flow.
C. An electric field forms.
D. A magnetic field forms.
The two correct answers are A and D ap3x approved!
A C and D
C because ofc when electric charge flow electric field is produced
Answer:
A & D
Explanation:
a cannon has a mass 2500. it fires a cannon-Ball during a routine exercise. the cannon is 1000 times heavier than the cannon ball. the cannon ball leaves the barrel at a horizontal velocity of 160 m/s. the cannon comes to rest 2 seconds after the cannon ball was fired. calculate the magnitude of average net force that causes the cannon to rest
Answer:
F = 200 [N]
Explanation:
To solve this problem we must use the principle of conservation of linear momentum, which can be calculated by means of the following equation.
[tex]P=m*v[/tex]
where:
P = lineal momentum [kg*m/s]
m = mass [kg]
v = velocity [m/s]
Now we must understand that the momentum is conserved before and after the firing of the cannon. Before firing the cannon we have the mass of the cannon and mass of the cannonball together at rest (speed = 0). After firing the cannon the cannonball moves forward with positive speed, while the cannon moves back (negative), in this way knowing the masses of each one we can determine the speed of the cannon.
[tex](m_{cannon}+m_{ball})*v_{1}=-(m_{cannon}*v_{2})+(m_{ball}*v_{3})[/tex]
where:
m_cannon = 2500 [kg]
m_ball = 2.5 [kg]
v₁ = 0 (velocity of the group before firing)
v₂ = velocity of the cannon after firing [m/s]
v₃ = 160 [m/s] (velocity of the cannonball after firing)
[tex](2500+2.5)*0 = -(2500*v_{2})+(2.5*160)\\v_{2}=0.16[m/s][/tex]
Now using the following equation of kinematics, we can calculate the acceleration.
[tex]v_{f}=v_{o}-a*t[/tex]
where:
Vf = final velocity = 0 (cannon comes to rest)
Vo = initial velocity = 0.16 [m/s]
a = acceleration [m/s²]
t = time = 2 [s]
[tex]0 = 0.16 - a*2\\2*a=0.16\\a = 0.08 [m/s^{2}][/tex]
With the value of acceleration, we can use Newton's second law which tells us that the forces acting on a body is equal to the product of mass by acceleration.
ΣF = m*a
where:
F = force [N] (units of Newtons)
m = mass = 2500 [kg]
a = acceleration = 0.08 [m/s²]
[tex]F = 2500*0.08\\F = 200 [N][/tex]
As the building collapses, the volume of air inside the building decreases, while the mass of the air stays the same. This means that the _____ of the air inside the building will increase.
Answer:
Density
Explanation:
if A=3i +2j+3k ,find the magnitude of A+B and A-B
Since vector B was not specified, I'll assume one at random. You can later answer your own question.
Answer:
[tex]\mid\mid \vec A+\vec B \mid \mid=\sqrt{105}[/tex]
[tex]\mid\mid \vec A-\vec B \mid \mid=\sqrt{149}[/tex]
Explanation:
Given:
[tex]\vec A=3\hat i +2\hat j+3\hat k[/tex]
And (assumed):
[tex]\vec B=-5\hat i +8\hat j-4\hat k[/tex]
Find the magnitude of
[tex]\vec A+\vec B[/tex]
[tex]\vec A-\vec B[/tex]
Given a vector
[tex]\vec P=x\hat i +y\hat j+z\hat k[/tex]
The magnitude of the vector is:
[tex]\mid\mid \vec P\mid \mid=\sqrt{x^2+y^2+z^2}[/tex]
First part:[tex]\vec A+\vec B =3\hat i +2\hat j+3\hat k-5\hat i +8\hat j-4\hat k[/tex]
[tex]\vec A+\vec B =-2\hat i +10\hat j-\hat k[/tex]
The magnitude of the sum is:
[tex]\mid\mid \vec A+\vec B \mid \mid=\sqrt{(-2)^2+10^2+(-1)^2}=\sqrt{4+100+1}[/tex]
[tex]\mathbf{\mid\mid \vec A+\vec B \mid \mid=\sqrt{105}}[/tex]
Second part:[tex]\vec A-\vec B =3\hat i +2\hat j+3\hat k-(-5\hat i +8\hat j-4\hat k)[/tex]
[tex]\vec A-\vec B =3\hat i +2\hat j+3\hat k+5\hat i -8\hat j+4\hat k[/tex]
[tex]\vec A-\vec B =8\hat i -6\hat j+7\hat k[/tex]
The magnitude of the difference is:
[tex]\mid\mid \vec A-\vec B \mid \mid=\sqrt{8^2+(-6)^2+7^2}=\sqrt{64+36+49}[/tex]
[tex]\mathbf{\mid\mid \vec A-\vec B \mid \mid=\sqrt{149}}[/tex]
A 1369.4 kg car is traveling at 28.9 m/s when the driver takes his foot off the gas pedal. It takes 5.1 s for the car to slow down to 20 m/s. How large is the net force slowing the car
Answer:
F = 2389.603 N
Explanation:
Given:
Mass m = 1,369.4 kg
Initial velocity u = 28.9 m/s
Final velocity v = 20 m/s
Time t = 5.1 s
Find:
Net force
Computation:
a = (v - u)/t
a = (20 - 28.9)/5.1
a = -1.745 m/s²
F = ma
F = (1369.4)(1.745)
F = 2389.603 N
Justify this statement "Density of the impure water is greater than of pure water.
Explaining the concept:
To explain this, we first need to know what density actually is:
Density is the mass of a given substance per unit volume, which means, that is the amount of mass present in unit volume (1 cm³ , 1m³)
Impure water is water, but with impurities added to it
Why is the density of Impure water is greater:
When we compare the mass of equal volumes of Water and Impure water, we will find that the mass of Impure water will be more, that is because the extra mass is of the impurities
Since impure water has impurities uniformly spread in it, we will find more matter in unit volume of Impure water than in Pure water
That is why the density of Impure water is greater
What would its weight be on Jupiter?
24.9N
Answer:
1.898 × 10^27 kg
Explanation:
thats how much it ways
If the magnitude of the electric field of an electromagnetic wave is 3x10^3 V/m, what is the the magntude of the magnetic field?
a. 1.1 x 10^-12 T
b. 9 x 10^11 T
c. 10^5 T
d. 10^-5 T
e. 3 x 10^3 T
Answer:
The value of the magnetic field is [tex]B = 1.0*10^{-5} \ T[/tex]
The correct option is d
Explanation:
From the question we are told that
The magnitude of the electric field is [tex]E = 3*10^{3} \ V/m[/tex]
Generally the magnitude of the magnetic field is mathematically represented as
[tex]B = \frac{E}{c}[/tex]
Here c is the speed of light [tex]c = 3.0*10^{8} \ m/s[/tex]
=> [tex]B = \frac{E}{c}[/tex]
=> [tex]B = \frac{3.0*10^{3}}{ 3.0*10^{8}}[/tex]
=> [tex]B = 1.0*10^{-5} \ T[/tex]
When water freezes, its volume increases by 9.05% (that is, equation). What force per unit area is water capable of exerting on a container when it freezes?
Answer:
1.991 × 10^(8) N/m²
Explanation:
We are told that its volume increases by 9.05%.
Thus; (ΔV/V_o) = 9.05% = 0.0905
To find the force per unit area which is also pressure, we will use bulk modulus formula;
B = Δp(V_o/ΔV)
Making Δp the subject gives;
Δp = B(ΔV/V_o)
Now, B is bulk modulus of water with a value of 2.2 × 10^(9) N/m²
Thus;
Δp = 2.2 × 10^(9)[0.0905]
Δp = 1.991 × 10^(8) N/m²
Please help It is Anatomy and Phys
Think about the last time you had your temperature taken. Describe the circumstances that led you to have your temperature taken, including the mechanism by which your temperature was measured (oral thermometer, ear thermometer, etc.), so that given the right equipment, you could demonstrate the technique yourself to another person. What would have been considered an abnormal temperature in that situation?
Answer:
the last time i had my tempature taken was at disney prings about a week ago -_- they used one of those gun things that dont touch u and the SHOVED me forward so i guess i was fine
Explanation:
Answer:
thermometer
Explanation:
A 80 kg parent and a 20 kg child meet at the center of an ice rink. They place their hands together and push. The parent pushes the child with a force of 25 N, what is the force acting on the parent?
Answer:
force acting on the parent = 25 N .
Explanation:
According to third law of Newton , there is equal and opposite reaction to every action . Here force by the parent on child is action and the force by child on parent is reaction . The former is given as 25 N so force by child on parent will also be 25 N .
Answer is 25 N .
. A horizontal steel spring has a spring constant of 40.0 N/m. What force must be applied to the spring in order to compress it by 10.0 cm?
Ans 4 more to be exact
Explanation:
Given values are:
Spring constant,
k = 40 N/mand,
x = 10 mThe force will be:
→ [tex]F = kx[/tex]
By substituting the values, we get
[tex]= 40\times 10[/tex]
[tex]= 400 \ N[/tex]
Thus the above answer is right.
Learn more about spring constant here:
https://brainly.com/question/15277652
A 1430 kg is moving at 25.6 m/s when a force is applied, in the direction of the cars motion. The car speeds up to 31.3 m/s. If the force is applied for 5.4 s what is the magnitude of the force
The car accelerates with magnitude a such that
31.3 m/s = 25.6 m/s + a (5.4 s)
→ a = (31.3 m/s - 25.6 m/s) / (5.4 s) ≈ 1.056 m/s²
Then the applied force has a magnitude F of
F = (1430 kg) a ≈ 1500 N
E=6.63E-34J-s*4.6E14 hz