Answer:
a. 0.2 A
Explanation:
Given;
voltage of the battery, V = 12 V
three resistance connected in series, R₁ = 15 Ω, R₂ = 21 Ω, R₃ = 24Ω
The equivalent resistance for series connection is calculated as;
Rt = R₁ + R₂ + R₃
Rt = 15Ω + 21Ω + 24Ω
Rt = 60 Ω
Apply Ohm's law to calculate the current n the circuit;
V = IRt
I = V/Rt
I = 12/60
I = 0.2 A
Therefore, the current in the circuit is 0.2 A
An initially uncharged sphere is on an insulated stand and isolated in a chamber. The charge on the sphere is monitored as a beam of monochromatic light shines on the sphere. Initially nothing happens. The wavelength of the light is slowly decreased. When the wavelength reaches a certain value, a positive charge is suddenly measured on the sphere. The wavelength is then held constant, and the charge continues to increase at a constant rate. The intensity of the beam is then increased without the wavelength being changed, and the rate of increase of the charge becomes greater.
Required:
a. In a coherent paragraph-length response, describe the cause of the charge on the sphere and the changes in the observations about the charge, in terms of physics principles.
b. An electron in the chamber is moving with speed 2×10^5m/s when it collides with a positron (a particle identical to an electron except for the sign of its charge) moving with the same speed in the opposite direction. The particles annihilate each other. How much energy is released due to the annihilation?
c. In another experiment, a beam of electrons with uniform wavelength λe is incident on a slit, where the width of the slit is much larger than λe. A detector is placed near the slit, but no diffraction pattern is observed. What change should be made that would result in a diffraction pattern? Indicate why this change is the one needed.
Answer:
a) E = K + Φ, b) ΔE = 1.64 10⁻¹³ J., c) λ = a
Explanation:
a) In this case it is an example of the photoelectric effect that was correctly described by Einstein assuming that the light ray is composed of a series of particles called photons, each one with an energy given by the Planck equation
E = h f
c = λ f
substituting
E = h c /λ
We can see from this equation that as the wavelength of the ray decreases the energy of each photon increases, the moment arrives that the energy is sufficient to remove an electron from the sphere, thus leaving an unbalanced positive charge, this description explains why the positive charge appears on the sphere; the minimum wavelength to remove an electron is
E = K + Φ
if K = 0
E =Φ
where fi is the work function of the material.
When the intensity of the ray increases according to Eintein's description, the number of photons increases, so if the number of photons increases, the number of shocks and the number of electrons expelled increases, therefore the unbalanced positive charge also increases.
b) the energy released in collision is the sum of the energy of each particle
for the electron
E = K + m c² = (pc) ² + (m c²) ²
where the moment is
p = γ m u
γ = [tex]\sqrt{1- (\frac{u}{c})^2 }[/tex]
γ = [tex]\sqrt {1- ( \frac{2 \ 10^5}{3 \ 10^8 })^2 } = \sqrt{1- (6.67 \ 10 ^{-4)^2 }[/tex]
γ ≅ 1
in this case since the speed of the particles is much less than the speed of light,
E = (m u) ² + (m c²) ²
E = m² (u² + c²)
E = 9.1 10⁻³¹ [(2 10⁵) ² + (3 10⁸) ²
E = 9.1 10⁻³¹ 9 10¹⁶
E = 8.2 10⁻¹⁴ J
the positron has an energy of equal magnitude, so when the two particles annihilate the energy change is
ΔE = 2E
ΔE = 2 (8.2 10⁻¹⁴)
ΔE = 1.64 10⁻¹³ J.
c) the expression that describes the diffraction process is
a sin θ = m λ
sin θ = m λ/ a
where a is the width of the slit and m in diffraction order
The greatest value that the sine function can have is 1
1 = m λ / a
λ = a / m
therefore we can see that to see the diffraction phenomenon the width of the slit must be greater than or equal to the wavelength
Part D- Isolating a Variable with a Coefficient In some cases, neither of the two equations in the system will contain a variable with a coefficient of 1, so we must take a further step to isolate it. Let's say we now have • 30 + 4D = 5 • 2C + 5D = 2 t to None of these terms has a coefficient of 1. Instead, we'll pick the variable with the smallest coefficient and isolate it. Move the term with the lowest coefficient so that it's alone on one side of its equation, then divide by the coefficient. Which of the following expressions would result from that process?
1. D= 5/4 - 3/4C
2. C= 5/3 - 4/3D
Part E- Now that you have one of the two variables in Part D isolated, use substitution to solve for the two variables. You may want to review the Multiplication and Division of Fractions and Simplifying an Expression Primers. Enter the answer as two numbers (either fraction or decimal), separated by a comma, with C first.
Answer:
D) D = [tex]\frac{5}{4} - \frac{3}{4} \ C[/tex], E) (C, D) = ( [tex]\frac{17}{7}, \ \frac{-4}{7}[/tex]
Explanation:
Part D) two expressions are indicated
3C + 4D = 5
2C +5 D = 2
let's simplify each expression
3C + 4D = 5
4D = 5 - 3C
we divide by 4
D = [tex]\frac{5}{4} - \frac{3}{4} \ C[/tex]
The other expression
2C +5 D = 2
2C = 2 - 5D
C = [tex]1 - \frac{5}{2} \ D[/tex]
we can see that the correct result is 1
Part E.
It is asked to solve the problem by the substitution method, we already have
D = [tex]\frac{5}{4} - \frac{3}{4} \ C[/tex]
we substitute in the other equation
2C +5 D = 2
2C +5 (5/4 - ¾ C) = 2
we solve
C (2 - 15/4) + 25/4 = 2
-7 / 4 C = 2 - 25/4
-7 / 4 C = -17/4
7C = 17
C = [tex]\frac{17}{7}[/tex]
now we calculate D
D = [tex]\frac{5}{4} - \frac{3}{4} \ \frac{17}{7}[/tex]
D = 5/4 - 51/28
D =[tex]\frac{35-51}{28}[/tex]
D = - 16/28
D = [tex]- \frac{4}{7}[/tex]
the result is (C, D) = ( [tex]\frac{17}{7}, \ \frac{-4}{7}[/tex] )
1. A 10.-ohm resistor and a 20. -ohm resistor are connected in series
to a voltage source. When the current through the 10.- ohm resistor
is 2.0 amperes, what is the current through the 20.-ohm resistor?
(5F)
a. 1.0 A
b. 2.0 A
C. 0.50 A
d. 4.0 A
A 10.-ohm resistor and a 20. -ohm resistor are connected in series
to a voltage source. When the current through the 10.- ohm resistor
is 2.0 amperes, what is the current through the 20.-ohm resistor?
Answer:
B --> 2.0 A
the current going through the 10.-ohm resistor is what goes through 20.-ohm resistor
The current through the 20Ω resistor is 2.0 A. Hence option B is correct.
What is Current ?Current is a flow of charges. it is denoted by i and expressed in ampere A. Mathematically it is expressed as i = q/t, where q is the amount of charge and t is time. Current is nothing but amount of charges flown in the unit time in the electric wire. Charge is expressed in coulomb C and time in second s. hence coulomb per second (C/s) is ampere A. Charge on electron is 1.60217663 × 10⁻¹⁹C which is called as elementary charge.
There are two types of the current, Convectional current and non-conventional current. Convectional current is the current flows from positive to negative. Non convectional current flows from negative to positive. Note that flow of electrons is from negative to positive. Hence direction of flow of conventional current is from positive to negative.
In this problem, two resistors are connected in series. In the series combination of resistor, same current flows through all resistor.
Hence current through 20Ω Resistor is 2.0A.
Hence option B is correct.
To know more about current :
https://brainly.com/question/13076734
#SPJ2.
Calculate the energy, wavelength, and frequency of the emitted photon when an electron moves from an energy level of -3.40 eV to -13.60 eV.
Answer:
(a) The energy of the photon is 1.632 x [tex]10^{-8}[/tex] J.
(b) The wavelength of the photon is 1.2 x [tex]10^{-17}[/tex] m.
(c) The frequency of the photon is 2.47 x [tex]10^{25}[/tex] Hz.
Explanation:
Let;
[tex]E_{1}[/tex] = -13.60 ev
[tex]E_{2}[/tex] = -3.40 ev
(a) Energy of the emitted photon can be determined as;
[tex]E_{2}[/tex] - [tex]E_{1}[/tex] = -3.40 - (-13.60)
= -3.40 + 13.60
= 10.20 eV
= 10.20(1.6 x [tex]10^{-9}[/tex])
[tex]E_{2}[/tex] - [tex]E_{1}[/tex] = 1.632 x [tex]10^{-8}[/tex] Joules
The energy of the emitted photon is 10.20 eV (or 1.632 x [tex]10^{-8}[/tex] Joules).
(b) The wavelength, λ, can be determined as;
E = (hc)/ λ
where: E is the energy of the photon, h is the Planck's constant (6.6 x [tex]10^{-34}[/tex] Js), c is the speed of light (3 x [tex]10^{8}[/tex] m/s) and λ is the wavelength.
10.20(1.6 x [tex]10^{-9}[/tex]) = (6.6 x [tex]10^{-34}[/tex] * 3 x [tex]10^{8}[/tex])/ λ
λ = [tex]\frac{1.98*10^{-25} }{1.632*10^{-8} }[/tex]
= 1.213 x [tex]10^{-17}[/tex]
Wavelength of the photon is 1.2 x [tex]10^{-17}[/tex] m.
(c) The frequency can be determined by;
E = hf
where f is the frequency of the photon.
1.632 x [tex]10^{-8}[/tex] = 6.6 x [tex]10^{-34}[/tex] x f
f = [tex]\frac{1.632*10^{-8} }{6.6*10^{-34} }[/tex]
= 2.47 x [tex]10^{25}[/tex] Hz
Frequency of the emitted photon is 2.47 x [tex]10^{25}[/tex] Hz.
Four passengers with combined mass 250 kg compress the springs of a car with worn out shock absorbers by 4.00cm when they enter it. Model the care and passengers as a single body on a single ideal spring. If the loaded has a period of vibration of 1.08 s, what is the period of vibration of the empty car?
Answer:
The time period of the empty car will be "1.00 s".
Explanation:
The given values in the question will be:
Mass,
m = 250 kg
Loaded car's time period will be:
T = 1.08 s
Shock absorbers compression,
x = 4 cm
or,
= 0.04 m
Now,
Weight of passengers will be:
⇒ [tex]F=mg[/tex]
[tex]=250\times 9.8[/tex]
[tex]=2450 \ N[/tex]
The spring constant of shock absorbers will be:
⇒ [tex]k=\frac{F}{x}[/tex]
[tex]=\frac{2450}{0.04}[/tex]
[tex]=61.250 \ N/m[/tex]
As we know,
Time period, [tex]T = 2 \pi\sqrt{\frac{M}{k} }[/tex]
On substituting the values, we get
[tex]1.08=2\pi \sqrt{\frac{M}{61250} }[/tex]
[tex]\frac{M}{61250}=0.02955[/tex]
[tex]M=0.02955\times 61250[/tex]
[tex]=1809.6 \ kg[/tex] (Total mass of car as well as its passengers)
Now,
The mass of the empty car will be:
⇒ [tex]m'=M-m[/tex]
[tex]=1809.6-250[/tex]
[tex]=1559.6 \ kg[/tex]
hence,
The time period of empty car will be:
⇒ [tex]T'=2\pi\sqrt{\frac{m'}{k} }[/tex]
[tex]=2\pi\sqrt{\frac{1559.6}{61250} }[/tex]
[tex]=2\pi \sqrt{0.0254}[/tex]
[tex]=1.003 \ s[/tex]
or,
[tex]=1.00 \ s[/tex]
what's is the best definition of AVERAGE SPEED?
Answer:
The average speed is the distance travelled divided by the time taken: Average speed=Distance travelledTime taken.
By how many times would the gravitational force between two objects decrease if the distance between the two objects was tripled?
Answer:
If the separation distance between any two objects is tripled (increased by a factor of 3), then the force of gravitational attraction is decreased by a factor of 9 (3 raised to the second power).
What did Europeans, africans and Americans trade as a result for the Colombian exchange
A. Railroad engineering ideas
B. Computer technology
C. Film production techniques
D. Agricultural knowledge
Also under the subject I meant to put social studies not physics.
Answer: Railroad engineering ideas
A circuit with 220 voltage is supplied with a fuse of 10 ampere.How many bulbs of 100 watt can be safely used in the circuit
A sound has a higher pitch than a bell. Which quantity must also be higher in this sound than in the bell?
O amplitude
O frequency
O wavelength
O speed
Answer:
frequency
Explanation:
The frequency must also be higher in this sound than in the bell because for high pitch the frequency must be high.
What is the frequency?It is defined as the number of waves that crosses a fixed point in one second, known as frequency. The unit of frequency is per second.
We have:
A sound has a higher pitch than a bell.
As we know, the sound has a high pitch if the vibration frequency is high, and a low pitch if the vibration frequency is low.
Thus, the frequency must also be higher in this sound than in the bell because for high pitch the frequency must be high.
Learn more about the frequency here:
brainly.com/question/27063800
#SPJ2
Violet light (410 nm) and red light
(685 nm) pass through a diffraction
grating with d = 3.33 x 10-6 m. What is
the angular separation between them
for m = 2?
Answer:10.03
Explanation:acellus
Select all the correct answers.
What happens when a ray of light moves from alr to water?
Its speed changes.
its color changes.
Its direction changes.
It's absorbed by water.
Answer:
it changes it's direction
Explanation:
When light travels from air into water, it slows down, causing it to change direction slightly. This change of direction is called refraction. When light enters a more dense substance (higher refractive index), it 'bends' more towards the normal line
Answer:
Hope this helps!
Explanation:
When light travels from air into water, it slows down, causing it to change direction slightly. This change of direction is called refraction. When light enters a more dense substance (higher refractive index), it 'bends' more towards the normal line.
A 1.5-kg ball is throw at 10 m/s. What is the balls momentum?
Answer : The momentum of ball is, 15 kg.m/s
Explanation :
Momentum : It is defined as the motion of a moving body. Or it is defined as the product of mass of velocity of an object.
Formula of momentum is:
where,
p = momentum = ?
m = mass = 1.5 kg
v = velocity = 10 m/s
Now put all the given values in the above formula, we get:
Therefore, the momentum of ball is 15 kg.m/s
PLEASE HELP ME ASAP!!!!
You have a 6.00 V power supply, and
a 30.0 ohm and a 75.0 ohm resistor.
Find the current flowing out of the
battery if the resistors are connected
in parallel.
Answer: 0.28 A
Explanation:
Answer:
.28
Explanation:
Acellus
If you build a circuit with 3 D batteries, what is the voltage of the circuit?
A) 3 volts
B) 4.5 volts
C) 3 Amps
D) 4.5 Ohms
Answer:
a
Explanation:
Answer:
d
Explanation:
What materials are difficult to charge because electrons easily flow through them?
Answer:
Conductors
Explanation:
Pls help! Tysm!!! :D
Answer:
Slowing a bike by applying the brkaes is an xmaple of acceleration
Explanation:
Tritium and helium-3 have the same number of nucleons, but tritium has one proton and two neutrons whereas helium-3 has two protons and one neutron. Without doing a calculation, decide which nucleus has a greater binding energy. Explain. (Select all that apply.)
a. This happens in part because the tritium nucleus has greater Coulombic repulsion.
b. This happens in part because the helium-3 nucleus has greater Coulombic repulsion between nucleons.
c. This happens in part because the tritium nucleus has an extra neutron enhancing the nuclear forces.
d. Helium-3 is more stable.
e. This happens in part because the helium-3 nucleus has fewer neutrons.
f. Tritium is more stable.
Answer:
Tritium is more stable.
This happens in part because the tritium nucleus has an extra neutron enhancing the nuclear forces.
Explanation:
The binding energy is the energy that holds nucleons together in the nucleus. It depends on the number of nucleons present in the nucleus. The greater the number of nucleons, the greater the binding energy.
Also, the more the number of neutrons in a nucleus, the greater the nuclear forces. Helium-3 has only one neutron while tritium has two neutrons. The extra neutron in tritium enhances the nuclear forces hence tritium has a greater binding energy than Helium-3
Tritium is more stable.this happens in part because the tritium nucleus has an extra neutron enhancing the nuclear forces.
What is binding energy?
The binding energy is the energy that holds nucleons together in the nucleus. It depends on the number of nucleons present in the nucleus.
The greater the number of nucleons, the greater the binding energy.Also, the more the number of neutrons in a nucleus, the greater the nuclear forces.
Helium-3 has only one neutron while tritium has two neutrons. The extra neutron in tritium enhances the nuclear forces hence tritium has greater binding energy than Helium-3
Thus tritium is more stable.this happens in part because the tritium nucleus has an extra neutron enhancing the nuclear forces.
To know more about binding energy follow
https://brainly.com/question/15582431
What is hydrometer? Describe its use and any one type of hydrometer.
Answer:
An instrument for measuring the density of liquids.
Explanation:
A hydrometer is an instrument used to determine specific gravity. It operates based on the Archimedes principle that a solid body displaces its own weight within a liquid in which it floats. Hydrometers can be divided into two general classes: liquids heavier than water and liquids lighter than water.
Thermohydrometers is one type of hydrometer.
A man rides a bike along a straight road at a constant speed for 5 minmin, then has a flat tire. He stops for 5 minmin to repair the flat, but then realizes he cannot fix it. He continues his journey by walking the rest of the way at a constant speed, which takes him another 10 min.
Required:
Use the particle model to draw a motion diagram of the man for the entire motion described here. Number the dots in order, starting with zero.
What is the period of a wave that completes 3 waves in 2 seconds?
P = 3÷2
= 1.5
Explanation:
hope it helps
Is it more fun on a swing with low or high amplitude? Explain.
A block of mass 3m is placed on a frictionless horizontal surface, and a second block of mass m is placed on top of the first block. The surfaces of the blocks are rough. A constant force of magnitude F is applied to the first block as shown in the figure. (a) Construct free-body diagrams for each block. (b) Identify the horizontal force that causes the block of mass m to accelerate. (c) Assume that the upper block does not slip on the lower block, and find the acceleration of each block in terms of m and F.
By Newton's second law, assuming F is horizontal,
• the net horizontal force on the larger block is
F - µmg = 3mA
where µmg is the magnitude of friction felt by the larger block due to rubbing with the smaller one, µ is the coefficient of static friction between the two blocks, and A is the block's acceleration;
• the net vertical force on the larger block is
4mg - 3mg - mg = 0
where 4mg is the mag. of the normal force of the surface pushing up on the combined mass of the two blocks, 3mg is the weight of the larger block, and mg is the weight of the smaller block;
• the net horizontal force on the smaller block is
µmg = ma
where µmg is again the friction between the two blocks, but notice that this points in the same direction as F. It is the only force acting on the smaller block in the horizontal direction, so (b) static friction is causing the smaller block to accelerate;
• the net vertical force on the smaller block is
mg - mg = 0
where mg is the magnitude of both the normal force of the larger block pushing up on the smaller one, and the weight of the smaller block.
(You should be able to draw your own FBD's based on the forces mentioned above.)
(c) Solve the equations above for A and a :
A = (F - µmg) / (3m)
a = µg
3. A dog walks 12 meters to the east and then 16 meters back to the west.
For this motion, what is the distance moved?
What is the magnitude and direction of the displacemeni?
Answer:
[tex]distance = 16 + 12 \\ = 28 \: meters \\ \\ displacement = {}^{ + } 12 + {}^{ - } 16 \\ = - 4 \: meters \\ magnitude = > |s| = 4 \: meters[/tex]
distance travelled/time taken gives?
Answer:
speed
Explanation:
Speed = distance travelled/time taken
Answer: Speed
Explanation:
Speed is defined as the rate of change of the position of an object in a direction. The speed of an object is calculated as the distance travelled divided by the time that is taken.
Speed is regarded as a scalar quantity since it has only direction but doesn't have magnitude. The answer to the above question is speed.
A bar magnet is held in place while another bar magnet is placed near it. The second bar magnet spins around and
attaches to the first magnet on one end. Which statement is correct about the energy stored in the magnetic field?
(1 point)
O The increase in the energy stored in the system is proportional to the increase in kinetic energy.
O The decrease in the energy stored in the system is proportional to the decrease in kinetic energy.
O The increase in the energy stored in the system is proportional to the decrease in kinetic energy.
O The decrease in the energy stored in the system is proportional to the increase in kinetic energy.
Answer:
o
Explanation:
the increase energy stored in thw system is proportional to the decrease in kinetic energy
The increase in the energy stored in the system is proportional to the decrease in kinetic energy.
What is energy stored in the system ?"The energy stored in the system means the sum of energies of both magnets when second magnet stop spin and stick with first magnet. It is clear that the rotational kinetic energy of second magnet decrease and becomes part of the system. Hence the increase in the energy stored in the system is proportional to the decrease in kinetic energy."
What is kinetic energy ?"Kinetic energy is a form of energy that an object or a particle has by reason of its motion. If work, which transfers energy, is done on an object by applying a net force, the object speeds up and thereby gains kinetic energy."
Know more about kinetic energy here
https://brainly.com/question/21245662
#SPJ2
Which ones are correct??
Answer:
blanket:thermal conductivity
as it conduct heat.
aquarium glass:transparency
as light can be transfered from one side to
another.
A person pulls a box across the floor with a rope. The rope makes an angle of 40 degrees tot he horizontal, and a total of 125 newtons of force is applied. How much work is done if the box is pulled for 25 meters?
Answer:
The angle formed of the rope with the surface = 40°
Force applied = 125Newtons
The displacement covered by the box =25metres
W= FDcos theta
[125×40×cos(40°) ] Joules
= [ (3125×0.76604444311)]Joules
= 2393.88888472 joules(ans)
Hope it helps
what is conductivity?
Answer:
Conductivity is the measure of the ease at which an electric charge or heat can pass through a material. A conductor is a material that gives very little resistance to the flow of an electric current or thermal energy.
Explanation:
brainliest plss