Answer:
a. 7.96 W/m² b. i. 0.205 V/m ii. 0.68 nT
Explanation:
(Part a) Calculate I, the intensity of the light incident on your book?
Intensity, I = Power, P/Area,A
I = P/A where P = 100 W and A = 4πr² where r = distance of source from book = 1 m.
So, I = P/A
= 100 W/4π(1 m)²
= 25/π W/m²
= 7.96 W/m²
(Part b) Find Eo and Bo, the amplitude of the electric and the magnetic fields of the EM waves emitted by the lamp.
i. Eo the amplitude of the electric field
Intensity, I = E²/cμ₀ where E = r.m.s value of electric field, c = speed of light = 3 × 10⁸ m/s and μ₀ = permeability of free space = 4π × 10⁻⁷ H/m
Thus, E = √(I/cμ₀)
substituting the values of the variables into the equation, we have
E = √(I/cμ₀)
E = √(7.96 W/m²/[3 × 10⁸ m/s × 4π × 10⁻⁷ H/m])
E = √(7.96 W/m²/120π H/s)
E = √(0.0211 Ws/Hm²)
E = 0.145 V/m
Now E = E₀/√2 where E₀ = maximum value of electric field
So, E₀ = √2E
= √2 × 0.145 V/m
= 0.205 V/m
ii. Bo the amplitude of the magnetic field
Since c = E₀/B₀ where c = speed of light = 3 × 10⁸ m/s
B₀ = E₀/c
= 0.205 V/m ÷ 3 × 10⁸ m/s
= 0.068 × 10⁻⁸ T
= 0.68 × 10⁻⁹ T
= 0.68 nT
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
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
Define 1ohm resistance
Answer:
1 ohm is equal to one volt (V)/ one ampere (1A) 1 Ohm is defined as the resistance of a conductor with a potential difference of 1 volt applied to the ends through which 1-ampere current flows. Ohms is the SI unit of electrical resistance.
Explanation:
I hope it's help u
A student rubs a rubber balloon on their hair for several seconds. The student then rubs a second rubber balloon on her hair for the same length of time. The student determines that the first rubber balloon is repelled by the second rubber balloon, but the first rubber balloon is attracted to her hair. Which of the following claims, with appropriate evidence, if any, supports the notion of the two- charge model? Justify your selection.
A. The first rubber balloon is repelled by the second rubber balloon, but the first rubber balloon is attracted to the hair. These results show that two charges must exist because certain combinations of charges attract and certain combinations of charges repel.
B. The first rubber balloon is repelled by the second rubber balloon. This result shows that the charge of both objects must have the same sign.
C. The first rubber balloon is attracted to the hair. This result shows that the charge of both objects must be opposite in sign.
D. None of the claims nor evidence support the notion of the two-charge model.
Answer:
Option A
Explanation:
In this experiment, when balloon is rubbed on the chair electrons are transferred from the hair to the surface of the balloon thereby making balloon negatively charged and hair positively charged. When two negatively charged balloon are brought close to each other, they repel while when balloon is brought closer to the hair, they attract each other
Hence, option A is correct
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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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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What is the total amount of force needed to keep a 6.0 kg object moving at speed
of 5.0 m/s? (F=ma)
A. 30 N
B. 60 N
C.ON
D. 10 N
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
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.
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.
You see a train that is moving toward you and sounding its
whistle at a constant frequency. Compared to the sound
produced by the whistle, the wavelength of the sound
observed by you is
Answer: shorter
Answer: shorter
Explanation:
HELPPP 40 POINTS!!!! Mr. Tedesco has two metal cubes, one made of
tin and the other made of silver. He heats the tin
cube to 80°C and places the silver one in the
freezer until it reaches 5°C. He places the cubes
in a beaker containing water at 20°C. The cubes
do not touch. Which best describes how heat
will flow in the system?
Answer: Heat energy is transferred from warmer objects to cooler objects.
Explanation:
(Will give Brainliest) Some scientists calculated that a whale can develop 150 kW of power when it is swimming under the water surface at a constant speed 7.77 m/s. Find the resistance force of the water exerted on the whale.
The resistance force of the water exerted on the whale is 19305 Newton.
What is power?
The quantity of energy moved or converted per unit of time is known as power in physics. The watt, or one joule per second, is the unit of power in the International System of Units. Power is also referred to as activity in ancient writings. A scalar quantity is power.
Power = 150 kW = 150,000 Watt.
Constant speed = 7.77 m/s.
Now, Power = the resistance force × speed
150000 Watt = the resistance force × 7.77 m/s
Hence, the resistance force = 150000 Watt/ 7.77 m/s
= 19305 Newton.
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If an object is placed 10cm in front of a converging lens that has a focal length of 15cm. What are the properties of the image?
Answer:
Enlarged [Size]
Virtual and Erect [Nature]
On the same side of the lens as the object [Position]
Explanation:
Wha is the definition of health?
Each of the different colors that make up white light has a different ___________________.
Answer:
Wavelength?
Explanation:
A proton traveling due north enters a region that contains both a magnetic field and an electric field. The electric field lines point due west. It is observed that the proton continues to travel in a straight line due north. In which direction must the magnetic field lines point
Answer:
upward
Explanation:
In the electromagnetic system of force if the direction of motion of proton does not changes it means that the electric and magnetic forces are such a ways that they are cancelling each other's effect.
Since, electric field lines will exert a force on the proton to the west, hence, the magnetic force must force it to the east. It is well known that magnetic force acts perpendicular to the direction of magnetic field. magnetic field should point upward direction.
True or False all elements emitt the same amount of light?
1 point
A.True
B.False
This 11.0-kg box is pulled 2.00 m to the right along the floor by applied
force
P
35.0 N at
O=
30.0
The coefficient of kinetic friction is
Mk
=
0.21. What is the magnitude of the work done by the kinetic friction
force? [Round your answer to the nearest whole number.]
ө
E
FR
Вk
Answer:
fffcdcffffdxxfxxtdyfycycycycy
Which of these uses the force of gravity to make it move?
OA
A sailboat moving across a lake
ОВ:
A car making a right turn
ОС:
A snow sled going downhill
OD
A bicycle rolling to a stop
Plz somebody help this is a test
Answer:
C: A snow sled going down hill
stephen stigler determined in 1977 that the speed of light is 299,710.5 km/sec. in 1882, albert michelson is there enough evidence to show that michelson's data is different from stigler's value of the speed of light? test at 5% level
Answer: hi your question is incomplete attached below is the complete question
answer :
population parameter( μ ) : mean speed of light measured by Albert Michelsonnull hypothesis ( H₀ ) : μ = 299,710.5km/s.Alternate hypothesis ( Hₐ ) : μ ≠ 299,710.5 km/secRandom variable : Speed of light measured by Albert Michelson.Explanation:
Using the information provided in the question attached I will match each term with its corresponding meaning
population parameter( μ ) : mean speed of light measured by Albert Michelson, here the parameter of interest is the speed of light measured/recorded by Albert which is represented as population mean μnull hypothesis ( H₀ ) : μ = 299,710.5km/s. given that the test is to determine if the speed of light recorded by both scientists are the sameAlternate hypothesis ( Hₐ ) : μ ≠ 299,710.5 km/sec. given that the test is to determine if the speed of light recorded by both scientists are the sameRandom variable ( x ) : Speed of light measured by Albert Michelson. her we are trying to bring to conclusion data measured by Albert Michelsonexample 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)
in the water circuit model which part represent the wire
1)pump
2)pipes
3)tap
Answer:
pipes
Explanation:
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)
A radio station broadcasts with a carrier frequency of 920 kHz. What is the wavelength of the radio waves?
a. 276 m
b. 175 m
c. 22.6 m
d. 326 m
e. 226 m
Answer: 326m
Explanation:
To find the the wavelength of the radio waves, we can use the equation:
Wavelength = c/f
where,
c = 3 × 10^8 m/s
f = 920 × 10^3 kHz
Wavelength = 3 × 10^8 / 920 × 10³
Wavelength = 326.08696
Wavelength = 326m
Please help me in science plss
I give brainliest to Answer this plss
Facts about ecstasy
Will give brainliest! 50 points!!!
When the polarity of a moving magnet through a coil doubles the electromagnetic field _________.
A. Increases
B. Decreases
C. Stays the same
Answer:
A. Increases
Explanation:
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Two train cars moving in the same direction are going to be coupled together. The mass of the first car is 5,000 kg and is moving at 5 m/s; the second car weighs the same, but is moving at 1 m/s. How fast will the two coupled cars move and how much kinetic energy does the system lose from coupling the cars together after they collide
Answer: [tex]3\ m/s,\ 20,00\ J[/tex]
Explanation:
Given
Mass of the first car [tex]m_1=5000\ kg[/tex]
Mass of the second car [tex]m_2=5000\ kg[/tex]
The velocity of the first car is [tex]v_1=5\ m/s[/tex]
The velocity of the second car is [tex]v_2=1\ m/s[/tex]
Conserving momentum, take [tex]v_o[/tex] as the velocity after coupling
[tex]\Rightarrow m_1v_1+m_2v_2=\left( m_1+m_2\right)v_o\\\Rightarrow 5000\times 5+5000\times 1=\left( 10,000\right)v_o\\\\\Rightarrow v_o=\dfrac{25,000+5000}{10,000}\\\\\Rightarrow v_o=\dfrac{30,000}{10,000}\\\Rightarrow v_o=3\ m/s[/tex]
[tex]\text{Initial kinetic Energy }K_1=\frac{1}{2}m_1v_1^2+\frac{1}{2}m_2v_2^2\\\\\Rightarrow K_1=\frac{1}{2}\times 5000\left( 5^2+1^2\right)\\\\\Rightarrow K_1=65,000\ J\\\\\\\text{Final Kinetic Energy}\ K_2=\frac{1}{2}\left(m_1+m_2\right)v_o^2\\\\\Rightarrow K_2=\frac{1}{2}\times 10,000\times 3^2\\\\\Rightarrow K_2=45,000\ J\\\\\text{Kinetic energy lost is equivalent to change in Initial and final energy i.e.}\\\\\Rightarrow K_1-K_2=65,000-45,000\\\\\Rightarrow K_1-K_2=20,000\ J[/tex]
The speed of sound is approximately 340 m/s.what is the wavelength of a sound wave with a frequency of 1000Hz
Answer:
34cm
Explanation: