Answer:
0.6 A
Explanation:
As the motor gears towards full speed, the voltage of the circuit tends to become the difference that exists between the line voltage and the that of the back emf. Remembering Ohm's law, we then apply it to get the final, lower current that is based on the reduced voltage Ef. We use the provided resistance in the question, that is 3 ohms.
Ef = (120 V) - (117 V) = 3 V
If = Ef/R = (3 V) / (5.0 Ω) = 0.6 A
A car starts from point A, goes 100 km to point B, immediately turns around, and returns to point A. The round trip takes 4 hours.
What is the average speed of the car?
Answer:
50 km/h
Explanation:
200 km = 4 hours
200/4=50
50km/h
PHYSICS! HELP ME PLEASE ASAP!
1.) If an ambulance passes you while you're walking your dog, a change in pitch is ____?
A.) not perceived by either the pedestrian or you
B.) perceived by the you
C.) perceived by the driver
2.) In the star wars movies, the soundtrack is very important. musicians and sound technicians spend weeks perfecting the noise of the light sabers, lasers, tie fighters and explosions. in real life, there would be no sound at all in space. Why?
A.) mechanical waves require a medium to travel
B.) sound is an electromagnetic wave
C.) mechanical waves do not require a medium to travel
D.) sound is a product of vibration
3.) what is a compression?
A.) region of zero pressure in a medium caused by a wave passing
B.)region of a high altitude in a medium caused by a passing wave
C.) region of a high pressure in a medium cause by a passing wave
D.) region of low pressure in a medium caused by a passing wave
Answer:
1B, 2B and 3C hope this helps
Explanation:
A spring of spring constant 25 N/m is hung vertically and a 0.300 kg mass is attached to one end, causing a displacement of the end of the spring of _____ m.
a. 0.01
b. 0.12
c. 0.77
d. all of the above
Answer:
The displacement of the spring is 0.12 m.
Explanation:
Given;
spring constant, k = 25 N/m
mass attached to the spring, m = 0.300 kg
displacement of the spring, x = ?
Apply Hook's law, weight of the mass attached (applied force) is directly proportional to the extension of the spring.
F = kx
mg = kx
0.3 x 9.8 = 25x
2.94 = 25x
x = 2.94 / 25
x = 0.12 m
Therefore, the displacement of the spring is 0.12 m.
In simple harmonic motion, the acceleration is proportional to In simple harmonic motion, the acceleration is proportional to:_________.
a. the amplitude.
b. the velocity.
c. the frequency.
d. the displacement.
e. all of the above
Answer:
e. all of the above
Explanation:
In simple harmonic motion, the acceleration is given as;
a = -ω²x = -(2πf)²x
[tex]a_{max} = -\omega ^2A[/tex]
where;
ω is the angular velocity
f is the frequency
x is the displacement
A is the amplitude
Thus, In simple harmonic motion, the acceleration is proportional to the amplitude, velocity, frequency, and displacement.
The correct option is E.
"all of the above"
When an element ejects an alpha particle, the mass number of that element
A.reduce by 4.
B.remains unchanged.
C.increase by 1.
D. reduce by 1.
Answer:
A.reduce by 4.
Explanation:
In Chemistry, an alpha particle which is typically a helium nucleus has an atomic mass (number of nucleons) of four (4). Therefore, the ejection of an alpha particle by any chemical element simply means that, the mass number of that particular chemical element would be reduced by four (4).
Basically, this process is referred to as an alpha decay and can be defined as a radioactive disintegration of a chemical element that causes it to emit an alpha particle and as a result reducing its mass number by four (4).
Hence, when an element ejects an alpha particle, the mass number of that element reduces by 4.
Which structures are found in the middle ear? Check all that apply.
A. hammer
B. anvil
C. ear canal
D. cochlea
E. ear drum
F. stirrup
Answer:
E, A, B, F
Explanation:
The Middle Ear contains:
eardrum.
cavity (also called the tympanic cavity)
ossicles (3 tiny bones that are attached) malleus (or hammer) - long handle attached to the eardrum. incus (or anvil) - the bridge bone between the malleus and the stapes. stapes (or stirrup) - the footplate; the smallest bone in the body.
Answer: rawr
Explanation:
hammer
anvil
ear drum
stirrup
What would be the magnitude of a star with a temperature of 25,000 located on
the main sequence?
Answer:
hvkhvkhvkvlhvgjvgv
Explanation:
What electromagnetic wave is a is a TV remtoe
Answer:
infared radiation
Explanation:
A force of 64 N gives an object an acceleration of 23.53 m/s^2. What is the mass of the object?
A-2.00 kg
B-1505 kg
C-2.72 kg
D-736 kg
A tsunami, an ocean wave generated by an earthquake, propagates along the open ocean at 700 km/hr and has a wavelength of 750 km. What is the frequency of the waves in such a tsunami?A. 6.8 HzB. 0.93 HzC. 0.00026 HzD. 1.1 HzE. 0.15 Hz
Answer:
C) 0.00026 Hz
Explanation:
In any wave, there exists a fixed relationship between the speed v, the frequency f and the wavelength λ, as follows:[tex]v = \lambda * f (1)[/tex]
Replacing by the givens in (1), and solving for f, we get:[tex]f = \frac{v}{\lambda} = \frac{700km/hr}{750 km} = 0.93 1/hr (2)[/tex]
Converting the units to Hz (1/sec), we get:[tex]f = 0.93 \frac{1}{hr} *\frac{1 hr}{3600sec} = 2.6e-4 = 0.00026 Hz (2)[/tex]
The answer C. is the right one.two spheres A and B are projected off the edge of a 1.0 m high table with the same horizontal velocity . sphere A has a mass of 20.g and sphere B has a mass of 10.g.
If both spheres leave the edge of the table at the same instant, sphere A will land
a. at some time after sphere B.
b. at the same time as sphere B.
c. at some time before sphere B.
d. There is not enough information to decide.
A would land before since its heavier
what is mean by combination reaction ?
[tex] \underline{\purple{\large \sf Combination \: reaction :-}} [/tex]
Those reaction in which two or more substances combine to form a one new substance are called Combination reaction
In this reaction, We can add :
Two or more elements can combine to form a compound.Two or more compounds can combine to from a one new compound.An element and a compound can combine to form a new compound.[tex] \underline{\green{\large \sf For\: example :}} [/tex]
[tex] \sf 2H_{2} + O_{2} \: \underrightarrow{Combination} \: 2H_{2}o[/tex]
In this, Hydrogen is an element and Oxygen is another element. Both are combined to form compound 'Hydrogen oxide'. Hydrogen oxide is commonly known as water.
An airplane wing is designed so that the speed of the air across the top of the wing is 297 m/s when the speed of the air below the wing is 209 m/s. The density of the air is 1.29 kg/m3. What is the lifting force on a wing of area 26.0 m2?
Answer:
The value is [tex]F_L = 759200 \ N[/tex]
Explanation:
From the question we are told that
The speed of air across the top of its wings is [tex]v = 297 \ m/s[/tex]
The speed of air below its wings is [tex]u = 209 \ m/s[/tex]
The density of air is [tex]\rho = 1.29 \ kg/m^3[/tex]
The area of the wing is [tex]A = 26.0 \ m^2[/tex]
Generally the lifting force is mathematically represented as
[tex]F_L = \Delta P * A[/tex]
Here [tex]\Delta P[/tex] is the difference in kinetic energy density between the top and the bottom
[tex]\Delta P = \frac{1}{2} * \rho * [v^2 - u^2 ][/tex]
=> [tex]\Delta P = \frac{1}{2} * 1.29 * [297^2 - 209^2 ][/tex]
=> [tex]\Delta P = 2.92 *10^{4} \ Pa[/tex]
So
[tex]F_L = 2.92 *10^{4} * 26.0[/tex]
=> [tex]F_L = 759200 \ N[/tex]
20 pts.
Which of the following statements is true?
O Electromagnets use electrlcity and magnets.
O Magnetic fields are strongest around the poles of a magnet.
O The south pole of a magnet will repel the south pole of another magnet.
O all of the above
Answer:
all are true so d is right
Explanation:
Electromagnets use electrlcity and magnets is true.
Magnetic fields are strongest around the poles of a magnet is true.
The south pole of a magnet will repel the south pole of another magnet is true
and since all of them is true the answer is d all of the above
A police officer standing at the side of the road uses a radar emitting frequency of 24.15 GHz. A car is going away from the officer at a speed of 50mph. What will be the difference in frequency of the beam reflected by the car received back by the radar?
a. 4.0 kHz (lower frequency)
b. 1.8 kHz (higher frequency)
c. 4.0 kHz (higher frequency)
d. 1.8 kHz (lower frequency)
Answer:
The correct answer is C
Explanation:
From the question we are told that
The frequency of the radar is [tex]f = 24.15 \ GHz = 24.15 *10^{9} \ Hz[/tex]
The speed of the car is [tex]v = 50 mph = \frac{50}{2.237} = 22.35 \ m/s[/tex]
Generally the difference frequency reflected by the car and the frequency which the radar receives back is mathematically represented as
[tex]\Delta f = \frac{f * 2 * v }{ c }[/tex]
Here c is the speed of light with value [tex]c = 3.0 *10^{8} \ m/s[/tex]
=> [tex]\Delta f= \frac{2 * 24.15 *10^{9} * 22.35}{ 3.0*10^{8}}[/tex]
=> [tex]\Delta f = 4000 \ Hz[/tex]
=> [tex]\Delta f = 4.0 \ kHz[/tex]
Given that the value is positive then it a higher frequency
Match the scienntist with their accomplishment / discoveries
Answer:
newton - motion, gravity
kepler - orbital paths
brahe - the sun goes around the earth
Explanation:
im not sure about brahe but its the only one that makes sense
For a polymer that was maintained at constant strain, an initial stress of 2.76 MPa decreases to 1.72 MPa after 6 hr. Estimate the stress remaining after 30 hr.
Answer:
1.48 Mpa
Explanation:
Given that For a polymer that was maintained at constant strain, an initial stress of 2.76 MPa decreases to 1.72 MPa after 6 hr. To estimate the stress remaining after 30 hr, we must first find the decay constant by using the exponential equation.
Therefore, the estimate of the stress remaining after 30 hr, is 1.48Mpa.
Please find the attached file for the solution.
Which factor listed below has the greatest effect on the period of a pendulum?
a
Mass of the pendulum
b
Angle of the pendulum
c
Length of the string
d
Amplitude of the oscillations
Answer:
C
Explanation:
equation for pendulum period is
[tex]\mathrm{T}=2 \pi \sqrt{\frac{\mathrm{L}}{\mathrm{g}}}[/tex]
and it depends only on its length (and gravity which is not on the list of answers)
1+1=?
FIRST ONE TO ANSWER GETS BRAINLIEST!
Answer:
Thx for points merry Christmas answer 2
Explanation:
Answer:2
Explanation:
true or false The most extreme tides occur during a new
moon and full moon.
Answer:
true
Explanation:
Help me please..
Speed is?
A) A measure of how fast something is moving
B) The distance covered per unit time
C) Always measured in terms of distance divided by time
D) All of the above
E) None of the above
C) Always measured in terms of distance divided by time.
A disk rotates at a constant angular velocity of 30 degrees per second. Consider a point on the edge of the disk. Through how many degrees has it rotated after 3 seconds?
Answer:
The disk covers a rotation of 90º after 3 seconds.
Explanation:
Since the disk rotates at constant angular speed, we can determine the change in angular position ([tex]\Delta \theta[/tex]), measured in sexagesimal degrees, by the following kinematic formula:
[tex]\Delta \theta = \omega\cdot \Delta t[/tex] (1)
Where:
[tex]\omega[/tex] - Angular velocity, measured in sexagesimal degrees per second.
[tex]\Delta t[/tex] - Time, measured in seconds.
If we know that [tex]\omega= 30\,\frac{\circ}{s}[/tex] and [tex]\Delta t = 3\,s[/tex], then the change in angular position is:
[tex]\Delta \theta = \left(30\,\frac{\circ}{s} \right)\cdot (3\,s)[/tex]
[tex]\Delta \theta = 90^{\circ}[/tex]
The disk covers a rotation of 90º after 3 seconds.
Help me please..
Velocity is defined as a
and a?
A) speed, direction
B) change, direction
C) speed, acceleration
D) change, acceleration
Answer:
Speed and direction.....
An astronaut stands on the surface of an asteroid. The astronaut then jumps such that the astronaut is no longer in contact with the surface. The astronaut falls back down to the surface after a short time interval. Which of the following forces CANNOT be neglected when analyzing the motion of the astronaut?
Asteroids are known through the help of artificial gravity, to have small gravity. The forces that cannot be neglected when analyzing the motion of the astronaut is that the gravitational force between the astronaut and the asteroid.
The gravitational force between two objects is said to be inversely proportional to the distance between them when squared. Therefore, when an individual halve the distance then the force increases by four times.
Unbalanced forces are simply known to be brought about due to a change in motion, speed, and/or direction. If two forces act in the same direction on an object, the net force is said to be equal to the sum of the two forces.
Learn more from
https://brainly.com/question/2784184
A gas cylinder holds 0.10 mol of O2 at 150 C and a pressure of 3.0 atm. The gas expands adiabatically until the pressure is halved
Part A
What is the final volume?
Part B
What is the final temperature?
Answer:
V2 = 1.899*10^-3 m^3
T2 = 347.125 K
Explanation:
Using gas law, we know that
PV = nRT,
Where
V1 = 0.00115743 m^3.
gamma = 1.4
Now, when we solve for final volume, V2 we get
V2 = V1/((P2/P1)^(1/gamma))
V2 = 1.899*10^-3 m^3
Using the same law and method, when we try to solve for the temperature, we find that the final temperature, T2 is
T2 = T1*((V1/V2)^(gamma-1))
T2 = 347.125 K
The final volume is 1.899*10^-3 m^3
And, the final temperature is 347.125 K
Gas law:here we used gas law,
we know that
PV = nRT,
Here
V1 = 0.00115743 m^3.
gamma = 1.4
Now final volume is
V2 = V1/((P2/P1)^(1/gamma))
V2 = 1.899*10^-3 m^3
Now the final temperature is
T2 = T1*((V1/V2)^(gamma-1))
T2 = 347.125 K
Learn more about volume here: https://brainly.com/question/13011592
Through what angle in degrees does a 33 rpm record turn in 0.32 s?
63°
35°
46°
74°
Answer:
1 rev = 2(pi) rad pi(rad) = 180 degrees
so 33 rev/min * 1 min/60s * (2*pi)rad/1 rev *180 deg/ pi rad * .32 s = 63.36 degrees
Explanation:
63.36 estimated to 63 so 63
The angle in degrees where 33 rpm record turn in 0.32 s should be considered as the 63 degrees.
Calculation of the angle:Since we know that1 rev = 2(pi) rad
So here pi(rad) = 180 degrees
Now for 33 rpm it should be like
= 33 rev/min * 1 min/60s * (2*pi)rad/1 rev *180 deg/ pi rad * .32 s
= 63.36 degrees
= 63 degrees
hence, The angle in degrees where 33 rpm record turn in 0.32 s should be considered as the 63 degrees.
Learn more about an angle here: https://brainly.com/question/3394547
A tennis ball moves 16 meters northward, then 22 meters southward, then 12 meters northward, and finally 32 meters southward.
Determine the magnitude of the distance the object traveled and the magnitude and direction of the displacement.
Answer:
The answer is 8m N
Explanation:
When a tennis ball moves 16 meters northward, then 22 meters southward, then 12 meters northward, and finally 32 meters southward. then the distance traveled by it is 82 m and the displacement covered by it is 26 m in a southward direction
What is displacement?
An object's position changes if it moves in relation to a reference frame, such as when a passenger moves to the back of an airplane or a professor moves to the right in relation to a whiteboard. Displacement describes this shift in location.
Displacement is a vector quantity. This indicates that it has both a direction and a magnitude and that it is visually represented as an arrow that points from the starting position to the ending position.
Thus, when a tennis ball travels 16 meters to the north, 22 meters to the south, 12 meters to the north, and 32 meters to the south. then it has a covered distance of 82 meters and has covered 26 meters of displacement in a southerly direction.
Learn more about displacement here
https://brainly.com/question/10919017
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WILL GIVE BRAINLEIST!!! PLEAAE HLEPNME
Which is most likely a chemical property? Oxidation state: the charge an atom has if it was bonded ionically to other atoms. Different oxidation states indicate different abilities to bond with other atoms. O Melting point: the temperature at which a solid turns into a liquid. Different substances have different melting points. O Density: the amount of a substance that fits in a certain volume. Different states of matter of the same substance can have different densities. O Conductivity: the ability to transfer electrical charges. Conductivity is different in different substances.
Answer:
Oxidation state: the charge an atom has if it was bonded ionically to other atoms. Different oxidation states indicate different abilities to bond with other atoms.
Explanation:
Oxygen and hydrogen are kept under the same temperature and pressure. Oxygen molecule is 16 times more massive than hydrogen one. The average speed of molecule of oxygen is:______.
Answer:
The average speed of molecule of oxygen is one-fourth of the speed of the hydrogen molecule.
Explanation:
The kinetic energy of gas molecule is given by following equation:
[tex]K.E = \frac{3}{2} KT[/tex]
Since the temperature (T) is constant for both molecules. Therefore, there kinetic energies will also be the same. Therefore,
[tex]K.E_{O_2} = K.E_{H_2}\\\frac{1}{2}m_{O_2}v_{O_2}^2 = \frac{1}{2}m_{H_2}v_{H_2}^2 \\\\but,\\\\m_{O_2} = 16m_{H_2}\\\\therefore,\\16 m_{H_2}v_{O_2}^2 = m_{H_2}v_{H_2}^2\\\\\\taking square root on both sides, we get:\\4v_{O_2} = v_{H_2}\\\\v_{O_2} = \frac{v_{H_2}}{4}[/tex]
The average speed of molecule of oxygen is one-fourth of the speed of the hydrogen molecule.
g A communication system operating at a power of 510 W produces electromagnetic radiation with a wavelength of 10.5 cm . Calculate the number of photons produced by the system per minute.
Answer:
The value is [tex]N = 2.69 *10^{26} \ photons[/tex]
Explanation:
From the question we are told that
The power is [tex]P = 510 \ W[/tex]
The wavelength is [tex]\lambda = 10.5 \ cm = 0.105 \ m[/tex]
Gnerally the number of photon produced is mathematically represented as
[tex]N = \frac{P * \lambda }{ h * c }[/tex]
Here [tex]h[/tex] is the Planck's constant with a value [tex]h = 6.62607015 * 10^{-34} J \cdot s[/tex]
c is the speed of light with value [tex]c = 3.0*10^{8 } \ m/s[/tex]
So
[tex]N = \frac{ 510 * 0.105 }{ 6.62607015 * 10^{-34} * 3.0 *10^{8} }[/tex]
=> [tex]N = 2.69 *10^{26} \ photons[/tex]