Answer:
3.46 A
Explanation:
electrical power = current × voltage
P = I × V
We have,
V = 7.8
P = 27
Thus, I = P ÷ V
I = 27 / 7.8
= 3.46 A
Which exercise type will improve a person's range of motion?
Answer:
stretching prior to an exercise is a great way to improve a range of motion, along with yoga and Pilates!
what do folds on a strip of paper mean
131_I_53 is an artificially made radioactive isotope of iodine, produced during the operation of nuclear power plants and the detonation of nuclear bombs. Exposure to high concentrations of 131 53I represents a serious risk for human health. However, small doses of this radioactive isotope are put to good use in medical studies. 131 53I is widely used in treating thyroid cancer and in diagnosis of abnormal liver and kidney function.
Required:
What is emitted when the radioactive nucleus of 131_I_53 decays to form the stable isotope of xenon 131_Xe_54?
Answer:
one beta particle
Explanation:
Since the atomic number of 131_I_53 increases by one to 131_Xe_54, we have the release of a beta particle since only a beta particle can cause a change in atomic number without a change in mass number. Since a beta particle is one electron, ₋₁⁰e, our nuclear equation is
¹³¹I₅₃ → ¹³¹X₅₄ + ₋₁⁰e
The atomic and mass numbers on both sides are balanced
mass number 131 = 131 + 0 = 131
atomic number 53 = 54 - 1 = 53
Thus a beta particle is emitted
You are at the top of the Empire State Building on the 102nd floor, which is located 373 mm above the ground, when your favorite superhero flies over the building parallel to the ground at 70.0 %% the speed of light. Part A You have never seen your favorite superhero in real life. Out of curiosity you calculate her height to be 1.57 mm . If the superhero landed next to you, how tall would she be when standing
Answer:
L₀ = 0.0022 m = 2.2 mm
Explanation:
Here, we will use the length contraction formula from the theory of relativity presented by Einstein:
[tex]L = L_o\sqrt{1-\frac{v^2}{c^2}}[/tex]
where,
L = Relative length = 1.57 mm = 0.00157 m
L₀ = actual length at rest = ?
c = speed of light
v = relative speed = 70% of c = 0.7 c
Therefore,
[tex]0.00157\ m = L_o\sqrt{1-\frac{(0.7\ c)^2}{c^2} }\\\\L_o = \frac{0.00157\ m}{\sqrt{1-0.49}}[/tex]
L₀ = 0.0022 m = 2.2 mm
what happens to an object as its thermal energy increases
Answer:
As the average kinetic energy of its particles increases, so does the thermal energy of the object. Therefore, the thermal energy of the object increases with increasing temperature
Answer: It gets hotter
Explanation:
When thermal energy increases, the object's particles gain kinetic energy, meaning they move faster. Therefore the particles move farther apart, causing the object to heat up.
A new planet has been discovered and given the name Planet X . The mass of Planet X is estimated to be one-half that of Earth, and the radius of Planet X is estimated to be twice that of Earth. The estimated mass and radius of Planet X are used to calculate the minimum escape speed, vc , for an object launched from the surface of the planet. If the actual mass and/or radius of the planet are slightly different from the estimated values.
Required:
How will the actual escape speed va for the surface of Planet X compare to vc?
Answer:
vₐ = v_c [tex]( \ 1 + \frac{1}{2} ( \frac{\Delta M}{M} - \frac{\Delta R}{R}) \ )[/tex]
Explanation:
To calculate the escape velocity let's use the conservation of energy
starting point. On the surface of the planet
Em₀ = K + U = ½ m v_c² - G Mm / R
final point. At a very distant point
Em_f = U = - G Mm / R₂
energy is conserved
Em₀ = Em_f
½ m v_c² - G Mm / R = - G Mm / R₂
v_c² = 2 G M (1 /R - 1 /R₂)
if we consider the speed so that it reaches an infinite position R₂ = ∞
v_c = [tex]\sqrt{\frac{2GM}{R} }[/tex]
now indicates that the mass and radius of the planet changes slightly
M ’= M + ΔM = M ( [tex]1+ \frac{\Delta M}{M}[/tex] )
R ’= R + ΔR = R ( [tex]1 + \frac{\Delta R}{R}[/tex] )
we substitute
vₐ = [tex]\sqrt{\frac{2GM}{R} } \ \frac{\sqrt{1+ \frac{\Delta M}{M} } }{ \sqrt{1+ \frac{ \Delta R}{R} } }[/tex]
let's use a serial expansion
√(1 ±x) = 1 ± ½ x +…
we substitute
vₐ = v_ c ( [tex](1 + \frac{1}{2} \frac{\Delta M}{M} ) \ ( 1 - \frac{1}{2} \frac{\Delta R}{R} )[/tex])
we make the product and keep the terms linear
vₐ = v_c [tex]( \ 1 + \frac{1}{2} ( \frac{\Delta M}{M} - \frac{\Delta R}{R}) \ )[/tex]
The minimum escape speed, vc , for an object launched from the surface of the planet will be [tex]v_a=v_c(1+\dfrac{1}{2}(\dfrac{\Delta M}{M}-\dfrac{\Delta R}{R})[/tex]
What is escape velocity of the planet?The escape velocity is defined as the velocity required to send the object out of the gravitational influence of the earth.
To calculate the escape velocity let's use the conservation of energy
starting point. On the surface of the planet
[tex]E_{mo} = K + U = \dfrac{1}{2} m v_c^2 - \dfrac{G Mm} { R}[/tex]
final point. At a very distant point
[tex]E_{mf} = U = \dfrac{- G Mm }{ R_2}[/tex]
energy is conserved
[tex]E{mo} = E{mf}[/tex]
[tex]\dfrac{1}{2}m v_c^2 - \dfrac{G Mm} {R} = \dfrac{- G Mm }{ R_2}[/tex]
[tex]v_c^2 = 2 G M (\dfrac{1} {R} - \dfrac{ 1 }{R_2})[/tex]
if we consider the speed so that it reaches an infinite position R₂ = ∞
[tex]v_c = \sqrt{\dfrac{2GM}{R}[/tex]
now indicates that the mass and radius of the planet changes slightly
[tex]M ’= M + \Delta M = M(1+\dfrac{\Delta M}{M})[/tex]
[tex]R ’= R + \Delta R = R (1+\dfrac{\Delta R}{R} )[/tex]
we substitute
[tex]vₐ = \sqrt{\dfrac{2GM}{R} }\dfrac{\sqrt{1+\dfrac{\Delta M}{M}}} {\sqrt{1+\dfrac{\Delta R}{R}}}[/tex]
let's use a serial expansion
√(1 ±x) = 1 ± ½ x +…
we substitute
[tex]v_a=v_c(1+\dfrac{1}{2}\dfrac{\Delta M}{M})(1-\dfrac{1}{2}\dfrac\Delta R}{R})[/tex]
Hence the minimum escape speed, vc , for an object launched from the surface of the planet will be [tex]v_a=v_c(1+\dfrac{1}{2}(\dfrac{\Delta M}{M}-\dfrac{\Delta R}{R})[/tex]
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A car is traveling at 20.0 m/s on tires with a diameter of 70.0 cm. The car slows down to a rest after traveling 300.0 m. If the tires rolled without slipping, what was the magnitude of the average angular acceleration of the tires during the time the car slowed to a rest
Answer: deceleration of [tex]1.904\ rad/s^2[/tex]
Explanation:
Given
Car is traveling at a speed of u=20 m/s
The diameter of the car is d=70 cm
It slows down to rest in 300 m
If the car rolls without slipping, then it must be experiencing pure rolling i.e. [tex]a=\alpha \cdot r[/tex]
Using the equation of motion
[tex]v^2-u^2=2as\\[/tex]
Insert [tex]v=0,u=20,s=300[/tex]
[tex]0-(20)^2=2\times a\times 300\\\\a=\dfrac{-400}{600}\\\\a=-\dfrac{2}{3}\ m/s^2[/tex]
Write acceleration as [tex]a=\alpha \cdot r[/tex]
[tex]-\dfrac{2}{3}=\alpha \times 0.35\\\\\alpha =-\dfrac{2}{1.05}\\\\\alpha =-1.904\ rad/s^2[/tex]
So, the car must be experiencing the deceleration of [tex]1.904\ rad/s^2[/tex].
The angular accelaration of a car traveling at 20.0 m/s on tires with a diameter of 70.0 cm, when car slows down to rest after traveling 300.0 m is 1.91 m/s
Angular acceleration: This can be defined as the rate of change of angular velocity. The s.i unit of angular acceleration is rad/s²
In other to solve the problem above, we will use the formula for calculating angular acceleration
a = αr.............. Equation 1
Where a = acceleration of the car's tires, α = angular acceleration of the car's tires, r = radius of the car's tires
Therefore,
α = a/r................. Equation 2
But, we need to calculate a using the equations of motion
v² = u²+2as................ Equation 3
Where v = final velocity = 0 m/s (rest), u = initial velocity= 20m/s, s = distance = 300 m
Substitute these values into equation 3
0² = 20²+2(300²)a
-400 = 600a
a = -400/600
a = -0.67 m/s²
going back to equation 2,
Given: r = 70/2 = 35 cm = 0.35 m
Substitute this values into equation 2,
α = -0.67/0.35
α = -1.91 rad/s²
Hence, the magnitude of the angular acceleration is 1.91 rad/s²
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Donna and Dave were participating in a lab on the properties of water. First, they tried to see how many drops of water they could fit on a penny. Then they dropped water and alcohol on waxed paper and observed what happened. Next they made a streak of water and then alcohol on the lab bench. The alcohol streak dried up and disappeared first. Donna and Dave had to write an explanation for everything that happened during the lab. How can they explain the disappearing alcohol? A) Alcohol is flammable. B) Alcohol has a lower boiling point than water. C) Alcohol has a lower melting point than water. D) Alcohol has a higher boiling point than water.
Answer:
D
Explanation:
D ok ok ok ok bye
The correct statement is that the alcohol has lower boiling point than water. The correct option is B.
What is boiling point?At the boiling point, the pressure exerted by the surroundings on a liquid equals the pressure exerted by the liquid's vapor, under this condition, adding heat outcomes in the transformation of the liquid into its vapor without raising the temperature.
The boiling point of alcohol is low. Because there is less hydrogen bonding between ethanol molecules than between water molecules.
The ethanol requires less energy to vaporize than water, and water has a higher boiling point than ethanol.
The boiling point of a liquid can be known by utilizing the capillary method, that encompasses placing an inverted capillary in the liquid of interest as well as heating it.
Thus, the correct option is B.
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Extrusive Igneous rock has ___________ grain size.
I need help on this one
Explanation:
Extrusive rocks may have a few grains that are large enough to see, but most of them will be too small to see individual minerals. ... The individual mineral grains are almost too small to see. Some extrusive rocks cool so quickly that they do not form any grains. Instead, they form a natural glass.
What happens to matter when it reaches absolute zero?
A. Its particles speed up.
O B. Its particles have no kinetic energy.
O C. Its particles vibrate slightly.
D. Its particles gain kinetic energy.
Answer:
O C. Its particles vibrate slightly.
Explanation:
At absolute zero, atoms would occupy the lowest energy state.They move much less than at higher temperatures, but they still have small vibrations at absolute zero.
Answer:
The answer is B its particles have no kinetic energy
Explanation:
trust the big brain
The low-frequency speaker of a stereo set produces 10.0 W of acoustical power. If the speaker projects sound uniformly in all directions, at what distance from the speaker is the intensity level 80.0 dB
Answer:
the required distance is 89.125 m
Explanation:
Given the data in the question;
we know that, sound intensity B in decibels of sound is;
β(dB) = 10log₁₀( [tex]I[/tex] / [tex]I_0[/tex] )
where intensity [tex]I[/tex] = power / area carried by wave
[tex]I_0[/tex] = 10⁻¹² W/m² { minimum threshold intensity }
Now,
intensity [tex]I[/tex] = power / area carried by wave = P/A = P/4πr² { spherical }
given that; β = 80.0 dB and P = 10 W
so
β(dB) = 10log₁₀( [tex]I[/tex] / [tex]I_0[/tex] )
we substitute
80 = 10log₁₀( P / 4πr²× [tex]I_0[/tex])
80 = 10log₁₀( 10 / 4πr²× 10⁻¹² )
8 = log₁₀(10) - log₁₀( 4πr²× 10⁻¹² )
8 = 1 - log₁₀( 4πr²× 10⁻¹² )
8 - 1 = -log₁₀( 4πr²× 10⁻¹² )
7 = -log₁₀( 1.2566 × 10⁻¹¹ × r² )
7 = -[ log₁₀( 1.25 × 10⁻¹¹) + log₁₀( r² ) ]
7 = -[ -10.9 + log₁₀( r² ) ]
7 = 10.9 - log₁₀( r² )
-log₁₀( r² ) = 7 - 10.9
-log₁₀( r² ) = - 3.9
log₁₀( r² ) = 3.9
2log₁₀r = 3.9
log₁₀r = 3.9 /2
log₁₀r = 1.95
r = 89.125 m
Therefore, the required distance is 89.125 m
Please help me in science plss
I give brainliest to Answer this plss
The photo shows a person pumping gasoline into a car
Which TWO of these energy transformations will occur when the car’s engine starts?
A. Chemical energy —> thermal energy
B. Chemical energy —> mechanical energy
C. Mechanical energy —> Chemical energy
D. Thermal energy —> chemical energy
Choose TWO
Answer:
A&B
Explanation:
Answer:
Chemical to mechanical(b) and Chemical to Thermal(a)
Z. A force that gives a 8-kg objet an acceleration of 1.6 m/s^2 would give a 2-kg object an
acceleration of
a. 0.2 m/s2
b. 0.4 m/s2
c. 1.6 m/s2
d. 6.4 m/s2
Answer:
[tex]\boxed {\boxed {\sf D.\ 6.4\ m/s^2}}[/tex]
Explanation:
We need to find the acceleration of the 2 kilogram object. Let's complete this in 2 steps.
1. Force of 1st ObjectFirst, we can find the force of the first, 8 kilogram object.
According to Newton's Second Law of Motion, force is the product of mass and acceleration.
[tex]F=m \times a[/tex]
The mass of the object is 8 kilograms and the acceleration is 1.6 meters per square second.
m= 8 kg a= 1.6 m/s²Substitute these values into the formula.
[tex]F= 8 \ kg * 1.6 \ m/s^2[/tex]
Multiply.
[tex]F= 12.8 \ kg*m/s^2[/tex]
2. Acceleration of the 2nd ObjectNow, use the force we just calculated to complete the second part of the problem. We use the same formula:
[tex]F= m \times a[/tex]
This time, we know the force is 12.8 kilograms meters per square second and the mass is 2 kilograms.
F= 12.8 kg *m/s²m= 2 kgSubstitute the values into the formula.
[tex]12.8 \ kg*m/s^2= 2 \ kg *a[/tex]
Since we are solving for the acceleration, we must isolate the variable (a). It is being multiplied by 2 kg. The inverse of multiplication is division. Divide both sides of the equation by 2 kg.
[tex]\frac {12.8 \ kg*m/s^2}{2 \ kg}= \frac{2\ kg* a}{2 \ kg}[/tex]
[tex]\frac {12.8 \ kg*m/s^2}{2 \ kg}=a[/tex]
The units of kilograms cancel.
[tex]\frac {12.8}{2}\ m/s^2=a[/tex]
[tex]6.4 \ m/s^2=a[/tex]
The acceleration is 6.4 meters per square second.
A 0.8 kg bead slides on a curved wire, starting
from rest at point A as shown in the figure.
The segment from A to B is frictionless, and
the segment from B to C is rough. The point
A is at height 7.1 m and the point C is at
height 2.5 m with respect to point B.
Find the speed of the bead at B. The acceleration due to gravity is 9.8 m/s2
Answer in units of m/s.
If the bead comes to rest at C, find the change
in mechanical energy due to friction as it
moves from B to C.
Answer in units of J.
a) The speed of the bead at B is 11.79m/s.
b) The change in mechanical energy due to friction as it moves from B to C is 36.064 J.
If we drop the object from the shelf or release the spring, that potential energy is converted back into kinetic energy. Kinetic energy can also be transferred from one body to another in a collision, which can be elastic or inelastic.
a)
Potential energy is converted to kinetic energy
[tex]\frac{1}{2} mv^2=mgh\\\\v=\sqrt{2gh} \\\\v_B=\sqrt{2(9.8)(7.1-0)} \\\\v_B=11.79m/s[/tex]
The speed of the bead at B is 11.79m/s.
b)
[tex]W = mg(h_A) - mg(h_B) = 0.8(9.8)(7.1 - 2.5) = 36.064 J\\\\W=36.064J[/tex]
The change in mechanical energy due to friction as it moves from B to C is 36.064 J.
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Positive electric charges are always attracted to ________ charges.
Answer:
Negative electric charges
When an electron in a certain excited energy level in a one-dimensional box of length 2.00 Å makes a transition to the ground state, a photon of wavelength 8.79 nm is emitted. Find the quantum number of the initial state?
Answer:
Calculate the wavelength associated with an electron with energy 2000 eV.
Sol: E = 2000 eV = 2000 × 1.6 × 10–19 J
What happens to matter when it reaches absolute zero?
A. Its particles speed up.
O B. Its particles have no kinetic energy.
O C. Its particles vibrate slightly.
D. Its particles gain kinetic energy.
Explanation:
It will be B.Its particles have no kinetic energy.
A 3 Volt battery is connected in series to three resistors: 4,6, and 2. Find the total resistance.
Answer:
The same current flows through each resistor in series. Individual resistors in series do not get the total source voltage, but divide it. The total resistance in a series circuit is equal to the sum of the individual resistances: RN(series)=R1+R2+R3+…
Each of the different colors that make up white light has a different ___________________.
Answer:
Wavelength?
Explanation:
When light passes from air to a different medium, as the density of the second medium increases, the angle of refraction ______
Answer:
Decreases
Explanation:
I think this is right tell me if it's wrong.
Answer:
Increases.
Explanation:
The density of the second medium increases, the angle of refraction also increases because of higher density of the medium. In more denser medium, there is more resistance for the light ray so it bends more as compared to less denser medium in which less bending of light ray occur. The angle of refraction increases when the density of medium is more than the previous medium so we can say that the angle of refraction increases due to increase in density of another medium.
Questions on the photo
Answer:
Option C: Third Class
Explanation:
This is third class because the effort or the input force is in the middle between the fulcrum and the load.
To solve this, we must be knowing each and every concept related to lever. Therefore, due to the effort or input force being in the center between the edge as well as the load, the supplied lever is of 3rd class. The correct option is option C.
What is lever?A lever is a basic device that consists of a beam or stiff rod located at a set tight, or edge. It is used to apply force to a load and often offers a mechanical advantage.
A stiff object that can rotate about a spot on itself is called a lever. The three types of levers are categorized according to where the edge, weight, and effort are located. Due to the effort or input force being in the center between the edge as well as the load, the supplied lever is of 3rd class.
Therefore, the correct option is option C.
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PLS ANSWER I NEED HELP
How is an electromagnetic wave (such as a radio wave) different from an ocean wave?
A) An electromagnetic wave cannot travel through empty space, but an ocean wave can.
B) An electromagnetic wave does not require a physical medium to travel through.
C) An electromagnetic wave is a longitudinal wave and an ocean wave is an oblong wave.
D) An electromagnetic wave travels more slowly than an ocean wave.
Answer:
mmmm im going to say B but i’m not sure
Explanation:
Electromagnetic waves can travel through air and unlike ocean waves or sound waves they do not need physical molecules for like a medium to travel
I've asked this question 5 times and still no answer pls help TT
What are three ways a driver can cause a car to accelerate?
A. Turn the key in the ignition while the car is stopped.
B. Turn the steering wheel while the car is moving.
C. Press the gas pedal while the car is stopped.
D. Press the brake pedal while the car is moving.
Answer:
c
Explanation:
the gas pedal gives the engine the fuel it needs to give the car the power to go
Ablock of mass m2 on arough horinzontal surfaceis connected to aball of mass m1 by alight weight cord over alight weight friction pulley as shownin figure .aforce of magnitude f at an angle
a mother and daughter press their hands together and then push apart while ice slating
Answer:
Lol nice
Explanation:
During an observation, it was noticed that light diffracts as it passes through small slits in a barrier. What does this evidence reveal about light?
It can travel in various wavelengths.
It can travel through the vacuum of space.
It demonstrates a behavior of energy.
It demonstrates a behavior of waves.
Answer:
It can travel in various wavelengths. brainliest?
Explanation:
The evidence that reveals about the light is that It can travel in various wavelengths.
What is diffraction?
It is the wave property that should be blending of the wave related to the corners.
At the time when the wave is bending so it passed via the openings.
Also, the light diffracted via the small slits and it should be shown to arise in the water waves and the sound waves.
hence, the first option is correct.
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Why might the current in a short circuit be higher than the current in the original circuit?
Answer:
Hope this helps =)
Explanation:
The current in a short circuit may be very high because the resistance in the short circuit is probably less than the resistance in the original circuit.
g An electron moves on a direction perpendicular to this page, into this page . The arrow below shows the direction of the magnetic field B present in this region. ----------------> B The direction of the magnetic force acting on the electron is directed
Answer:
force on the electron is upwards
Explanation:
The magnetic force is given by the relation
F = q v x B
the bold indicates vectors, we can write the module of this expression
F = q v B sin θ
the direction of the force is given by the right hand rule.
If we have a positive charge, the flea points in the direction of velocity, in this case towards the inside of the page.
fingers extended in the direction of the magnetite field, in our case to the right and
the palm gives the direction of the force for a positive charge, for a negative charge it is in the opposite direction. The palm points downwards, so the force on the electron is upwards
example of nuclear fission and nuclear fusion
Answer:
In fission, energy is gained by splitting apart heavy atoms, for example uranium, into smaller atoms such as iodine, caesium, strontium, xenon and barium, to name just a few. However, fusion is combining light atoms, for example two hydrogen isotopes, deuterium and tritium, to form the heavier helium.
Explanation:
I hope this helped you
(Sorry If it didn't)