Answer:
true
Explanation:
Answer:
true
Explanation:
A charged cell phone has chemical energy stored in its battery. As you use your phone, the amount of chemical energy in the battery decreases. Why is this not a violation of the first law of thermodynamics?
Answer:
Because the chemical energy is converted to electrical enegy in the cell phone
Explanation:
This set up is not a voilation of the first law of thermodynamics because the chemical energy is not lost, it is only being transformed into electrical energy.
According to the first law of thermodynamics "energy is neither created nor destroyed but transformed from one form to another".
In a charged cell phone, the chemical energy is being transformed to electrical energy as you use it. A phone cannot directly be powered with chemical energy. The energy transformation to electrical energy makes it possible to use the phone. In this process no energy is lost nor created. But simply, energy is transformed.It does not violate the first law of thermodynamics as the energy is being converted from one form to another.
Conversion of energy:As we use our phones, the amount of chemical energy in the battery decreases. But it is not a violation of the first law of thermodynamics.
It may seem like the first law of thermodynamics is being violated here as the chemical energy of the cell is decreasing but that's not the case.It is because the chemical energy in the battery is being converted into electrical energy.There is no energy being created or lost here. It is a simple conversion of energy from one form to another.The conservation of energy is being followed as the loss of chemical energy is equal to the gain in electrical energy of the system.Learn more about energy conversion:
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If an object starts at rest, what is necessary to make it start moving?
It will need a force acceleration
The variable that you/I the researcher get to choose.
Independent Variable
Dependent Variable
Experimental
Control
Answer:
Independant Variable
This athlete loads a sled to a combined mass of 90.0 kg, and drags the sled with a force of 258 N at an angle of 15.0° across a surface with a coefficient of kinetic friction of 0.250. What is the approximate acceleration of the sled?
Group of answer choices
Answer:
The approximate acceleration of the sled is 0.319 m/s²
Explanation:
Given;
mass of the sled, m = 90 kg
horizontal applied force, f = 258 N
angle of inclination of the force, θ = 15°
coefficient of kinetic friction of 0.250, μ = 0.25
The net vertical force on the sled is given by;
Fcosθ - μmg = ma
258Cos15 - (0.25 x 90 x 9.8) = ma
249.2 - 220.5 = ma
28.7 = ma
a = 28.7 /m
a = 28.7 / 90
a = 0.319 m/s²
Therefore, the approximate acceleration of the sled is 0.319 m/s²
The average speed of a car that travels 500 km in 5 hours is
Answer:
100km/h
Explanation:
500km/5 = 100km per hour
One mole of copper at a uniform temperature of 0° C is placed in thermal contact with a second mole of copper which, initially, is at a uniform temperature of 100° C. Calculate the temperature of the 2-mole system, which is contained in an adiabatic enclosure, when thermal equilibrium is attained. Why is the common uniform temperature not exactly 50° C? How much thermal energy is transferred, and how much entropy is produced by the transfer? The constantpressure molar heat capacity of solid copper varies with temperature as cp = 22.64 + 6.28×10−3T J/mole K
Answer:
1) T ≈ 50.318°C
2) It is due to the variation of the molar heat capacity of solid copper with temperature
3) The entropy introduced in the one mole of copper at 0°C is 4.146 J/K
The entropy introduced in the second mole of copper at 100°C is -3.548 J/K.
Explanation:
1) The given parameters are;
The temperature of 1 mole of copper = 0°C
The temperature of the second mole of copper 100°C
The specific heat capacity of copper = 22.64 + 6.28 × 10⁻³·T J/(mole·K)
The heat gained by the copper at 0° = The heat lost by the one mole of copper at 100°C
The total heat gained and lost is given as follows;
[tex]\int\limits^{T_f}_{273} {c_p} \, dT= -\int\limits^{T_f}_{373} {c_p} \, dT[/tex]
[tex]\int\limits^{T_f}_{273} {22.64 + 6.28 \times 10^{-3}\cdot T} \, dT= -\int\limits^{T_f}_{373} {22.64 + 6.28 \times 10^{-3}\cdot T} \, dT[/tex]
22.64·([tex]T_f[/tex] - 273) + (6.28 × 10⁻³)/2×([tex]T^2_f[/tex] - 273²) = - 22.64·([tex]T_f[/tex] - 373) - (6.28 × 10⁻³)/2×([tex]T^2_f[/tex] - 373²)
Which gives;
0.00314 × [tex]T^2_f[/tex] + 22.64 × [tex]T_f[/tex] - 6414.74 = -0.00314 × [tex]T^2_f[/tex] - 22.64 × [tex]T_f[/tex] + 8881.59
Transferring the right hand side of the equation to the left and collecting the like terms gives approximately;
0.00628× [tex]T^2_f[/tex] + 45.28 × [tex]T_f[/tex] - 15296.33 = 0
Factoring with a graphing calculator, gives;
(T + 7533.509)·(T - 323.318)×0.00628 = 0
∴ T = 323.318 K ≈ 50.318°C
2) The common uniform temperature is not exactly 50°C because the hotter second mole of copper had a higher specific heat capacity, which resulted in the temperature at equilibrium being slightly higher than the average temperature
3) The amount of thermal energy transferred is given as follows;
22.64·(323.318 - 273) + (6.28 × 10⁻³)/2×(323.318² - 273²) ≈ 1233.42 J
4) For the mole at 0°C, we have;
[tex]\Delta S_1 = \dfrac{\Delta Q}{T} =\int\limits^{323.318}_{273} { \left (\dfrac{22.64}{T} + 6.28 \times 10^{-3} \right)} \, dT\\\\\\\Delta S_1 = 22.64 \times ln \left ( \dfrac{323.318}{273} \right ) + 6.28 \times 10^{-3} \times (323.218 - 273) = 4.146 \ J/K[/tex]
The entropy introduced in the one mole of copper at 0°C, ΔS₁ = 4.146 J/K
For the mole at 100°C, we have;
[tex]\Delta S_2 = \dfrac{\Delta Q}{T} =\int\limits^{323.318}_{373} { \left (\dfrac{22.64}{T} + 6.28 \times 10^{-3} \right)} \, dT\\\\\\\Delta S_2 = 22.64 \times ln \left ( \dfrac{323.318}{373} \right ) + 6.28 \times 10^{-3} \times (323.218 - 373) = -3.548 \ J/K[/tex]
The entropy introduced in the second mole of copper at 100°C, ΔS₂ = -3.548 J/K.
Explain the meaning of the name "black hole". This should be 2-3 sentences. Hint- relate this to density and how it effects things. *
How did the motion of the ball change when John kicked it?
A
The ball continued moving in the same direction and its speed increased.
B
The ball continued moving in the same direction and its speed decreased.
C
The ball changed directions and its speed increased.
D
The ball came to a complete stop.
Answer:
The ball continued moving in the same direction and its speed increased.
When John kicked the ball, this was an example of motion. The ball's force increased because the ball got force from John's leg. So, the answer is option A.
Hope this helps you!
What is a new technology that is now being used to treat cancer?
Answer:
Another new technology in cancer treatment is Image Guided Radiation Therapy (IMGT), which also employs linear accelerators. IMGT allows for even more precise radiation treatment because it uses technology that can recognize the size and shape of the tumor within the body.
Explanation:
Anyone get this please help me step by step
Explanation:
Okayyy.. So..
12 pounds = 26.00
1 pound=2.17
Now you have to use cross multiplication method
[tex]1 = 2.17 \\ = 18.00[/tex]
The answer is 8.3
If I'm not mistaken
a) We produce a diffraction pattern on a viewing screen by means of a long narrow slit illuminated by blue light. Does the pattern expand away from the bright center (the maxima and minima shift away from the center) or contract toward it if we I. switch to yellow light or II. Decrease the slit width? 02 x 02 = 04 Marks
Answer:
I. The angle θ increases, and the pattern expands away from the bright center
II. The angle θ increases, and the pattern expands away from the bright center
Explanation:
The given information are;
The light used to produce a diffraction pattern = Blue light
The formula for refraction is given as follows;
d × sin(θ) = n·λ
Where;
d = The inter slit distance
θ = The angle to the maxima
n = Number to the integer next fringe
λ = Light wavelength
The wavelength of blue light is between 450 and 495 nanometers
Therefore;
I. When we switch to yellow light
The wavelength of yellow light is between 590 and 560 nanometers, which is an increase in wavelength, given that d, the inter slit distance is held constant, the angle θ increases, and the pattern expands away from the bright center
II. Decrease the slit width
When the slit width is decreased, and the wavelength remains the same, the angle θ increases, and the pattern expands away from the bright center.
Force is defined as
Change in momentum b)rate of change of momentum
c)The quantity that opposes inertia d)The quantity that keeps the velocity constant
Answer:
c) the quantity that opposes inertia
Ruth throws a baseball straight up at 22 m/s. What is the ball's velocity after 1.4 seconds?
Answer: v = 43.98 m/s
Explanation: 22 + 15.7x1.4 = 43.98.
Hope this helps!
A car traveling at 40 m/s accelerates to 57 m/s in 2.5 seconds. What is the acceleration of the car?
Answer:
6.8ms²
Explanation:
a=v-u/t
a=57-40/2.5
a=17/2.5
a=6.8ms²
Plz help i need help on my homework
Suppose you want to determine the electric field in a certain region of space. You have a small object of known charge and an instrument that measures the magnitude and direction of the force exerted on the object by the electric field. (a) The object has a charge of +25.0 μC and the instrument indicates that the electric force exerted on it is 40.0 μN, due east. What are the magnitude and direction of the electric field? E = (b) What are the magnitude and direction of the electric field if the object has a charge of -10.0 μC and the instrument indicates that the force is 40.0 μN, due west? E = (Chp18,p13GO)
Answer:
(a) 1.6 N/C, due east.
(b) 4 N/C, due east.
Explanation:
The force vector,[tex]\vec {F}[/tex] on the charge, q, in the electric field vector, [tex]\vec{E}[/tex], is
[tex]\vec {F}=\vec{E}q[/tex]
[tex]\Rightarrow \vec{E}=\frac{vec{F}}{q}\;\cdots(i)[/tex]
Let the unit vector towards east is [tex]\hat{i}[/tex], so the unit vector towards west is -
(a) Given that:
[tex]q=+25 \mu C[/tex],
[tex]\vec{F}=40.0 \mu N[/tex], due east
[tex]\Rightarrow \vec{F}=40.0 \mu N (\hat{i})[/tex]
From equation (i)
[tex]\vec{E}=\frac{40.0 \mu N (\hat{i})}{25 \mu C}=1.6(\hat{i}) N/C[/tex]
So, the magnitude of electric field is 1.6 N/C and the direction is towards east.
(b) Given that:
[tex]q=-10.0 \mu C[/tex],
[tex]\vec{F}=40.0 \mu N[/tex], due west
[tex]\Rightarrow \vec{F}=40.0 \mu N (-\hat{i})[/tex]
From equation (i)
[tex]\vec{E}=\frac{40.0 \mu N (-\hat{i})}{-10 \mu C}=-4(\hat{i}) N/C[/tex]
[tex]\Rightarrow \vec{E}=4(\hat{i}) N/C[/tex]
So, the magnitude of electric field is 4 N/C and the direction is towards the east.
-A pool ball leaves a 0.70 meter high table with an initial velocity of 2.4 m/s. Predict the time required for the pool ball to fall to the ground.
-A rock is thrown with a velocity of 23.7 m/s horizontally off the top of a bridge and lands in the water 35.0 meters away. What is the vertical velocity just before the rock hits the water below?
-A plane moving at a velocity of 205 m/s drops a piece of cargo which lands 6.5 seconds later. How far did the cargo box land after it's release?
Answer:
0.70+2.4=23.7+35.0=answer
Explanation:
Answer:
First Question:
If the initial velocity is horizontal: It doesn't really matter how fast it is going horizontally if we want to calculate time.
Since it rolled off the table, the initial vertical velocity is 0. The displacement will be -0.7 meters since the table is 0.7 meters high. The acceleration will be -9.8 m/s^2 because that's just earth's gravity.
We can plug the variables into the formula Displacement = Initial Velocity*Time + 1/2*Acceleration*Time^2:
[tex]-0.7 = 0\cdot t + 1/2\cdot-9.8\cdot t^2\\-0.7 = -4.9*t^2\\t^2 = \frac{10}{7} \\t = \sqrt{\frac{10}{7}}[/tex]
Rounded to the nearest hundredths, the answer is 1.2 seconds.
Second Question:
We can use the horizontal variables to find out the time to solve for the vertical velocity.
The acceleration is going to be 0(assuming no air resistance), the initial velocity is going to be 23.7 m/s, and the displacement is going to be 35.0 meters.
Again, we can plug the variables into the formula Displacement = Initial Velocity*Time + 1/2*Acceleration*Time^2:
[tex]35 = 23.7\cdot t + 1/2\cdot 0\cdot t^2\\35 = 23.7\cdot t\\t = \frac{35}{23.7}[/tex]
Rounded to the nearest hundredth, t = 1.48.
Now, we're going to find the vertical variables:
The acceleration will be -9.8 m/s^2 because that's just earth's gravity. The initial velocity will be 0 because the rock was launched horizontally. The time, as calculated before, is 1.48.
Now, we can plug t into the formula Velocity = Initial Velocity + Acceleration *Time:
[tex]v = 0 + -9.8\cdot1.48\\v = -14.504[/tex]
Rounded to the nearest hundredth, the answer is -14.5 meters per second.
Third Question:
Let's find the horizontal variables:
Assuming no air resistance, the final velocity is 205 m/s. The initial velocity will also be 205 m/s. The time will be 6.5 seconds.
We can use the formula Displacement = (Final Velocity+Initial Velocity)/2 * Time. In this case, the final velocity and the initial velocity are the same, so the formula reduces to Displacement = Final Velocity * Time:
[tex]d = 205\cdot6.5\\d = 1332.5[/tex]
Therefore, the answer is 1332 meters.
I really hoped this helped you because I spent more than 1 hour explaining. If you have more questions don't hesitate to ask. If it helped you, please consider giving me brainliest? :)
define heat...and angle of friction?
Explanation:
Heat is the form of energy that is transferred between systems or objects with different temperatures.....
Angle of friction : The angle which the resultant of force of limiting friction F and normal reaction R makes with direction of normal reaction R is called angle of friction...
physics the angle of a plane to the horizontal when a body placed on the plane will just start to slide. The tangent of the angle of friction is the coefficient of static friction.
what is an objects center of gravity
A) the exact center of its mass
B) the part that is closest to earth
C) any part of an object , as long as it has mass
D) all of the above
Answer:
the exact center of its mass
the efficiency of transformer is not 100%why?
Answer:
Hysteresis, Eddy current, flux leakage and resistance of winding are those four reasons. It is impossible to overcome this four reasons, Hence transformer never be 100% efficient.
What is a disadvantage of the inefficiency of cars?
Group of answer choices
Tire wear
low speeds of cars
time it takes to get somewhere
air pollution
someone help please
As the spaceship travels upward in the sky, some of its kinetic energy will be lost to the universe due to ?
a) Friction
b) Chemical Potential Energy
c) Temperatures decreasing as altitude increases
Answer:
Friction !!!
Explanation:
A decomposition ________ occurs when a substance is broken down into two or more simpler substances in a chemical reaction.
(APEX)
need the answer as fast as possible
Answer:
Element is the answer ok
Solar radiation is absorbed by the ocean. The absorbed energy evaporates water from the ocean. As water vapor (mass) enters the atmosphere it carries with it the heat used to evaporate the water and raises the air's humidity. What type of system is the ocean?
Answer:
open system
Explanation:
The open system type of system is the ocean option (C) open system is correct.
What is solar energy?It is defined as the energy that continuously comes from the sun. As we know, the sun is the greatest source of energy. The sun's radiation reaches the earth and can be utilized as heat energy.
The question is incomplete.
The complete question is:
Solar radiation is absorbed by the ocean. The absorbed energy evaporates water from the ocean. As water vapor (mass) enters the atmosphere it carries with it the heat used to evaporate the water and raises the air's humidity. What type of system is the ocean?
isolated systeminteractive systemopen systemclosed system
As we know,
An open system is one that responds to the movement of information, energy, and/or material between both the and its surroundings.
Thus, the open system type of system is the ocean if the water vapor (mass) enters the atmosphere it carries with it the heat used to evaporate the water and raises the air's humidity.
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3. What is the instantaneous speed of a car after 3 seconds that is traveling at 30 m/s and accelerates at a constant
rate of 10m/s??
How much clothes should be applied on 100 cm² area using pressure of 25 Pa
Answer:
hi !
Pressure = Force/Area
Force = Pressure*Area
Pressure = 25 Pa
Area = 100 cm² = 0.01 m²
F = 25*0.01
= 0.25 N
Explanation:
How do stars serve as evidence for the expansion of the universe and the Big Bang theory?
Answer:
The Doppler red-shift of light observed from distant stars and galaxies gives evidence that the universe is expanding (moving away from a central point). This allows for Big Bang Theory, because after a “bang” occurs all of the matter moves away from the point of origin.
The part of a longitudinal wave where the particles are spread apart is called a______?
Answer:
Rarefaction (I think so..)
The part of a longitudinal wave where the particles are spread apart is called a rarefactions.
What is longitudinal wave?Longitudinal waves are waves in which the displacement of the medium is in the same (or the opposite) direction as the wave propagation and the medium vibration is parallel ("along") to the direction the wave travels.
Because they create compression and rarefaction when passing through a material, mechanical longitudinal waves are also known as compressional or compression waves. They are also known as pressure waves because they cause pressure changes.
The part of a longitudinal wave where the particles are spread apart is called a rarefactions and the part of a longitudinal wave where the particles are closed together is called a compression.
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Energy must be measured in
Answer:
joule
Explanation:
hop it helps give a good rate ples
Answer:
joule
Explanation:
If your
is strong, it benefits your whole body both now and in the future. A strong muscular system helps you in three main ways:
1. You will have better long term health.
2. You will have better performance in activities.
3. You will have improved appearance.
A strong muscular system helps you in having good health for long life.
What is muscular system?The muscular system is made up of specialized cells called as muscle fibers.
Their main function is contractibility. Muscles are attached to bones, internal organs as well as blood vessels which make movement better.
Almost all body movement is due to muscle contraction. If your willpower is strong, it benefits your whole body both now and in the future. Will power helps us strengthen our thought in mind and the urge to keep ourselves happy and healthy.
Thus, a strong muscular system helps you in keeping healthy for long.
Learn more about muscular system.
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