Answer:
The number of photons of light produced by the laser in 1 hour is
1 Photon / hour
Explanation:
Number of photons of light produced is given by
[tex]Number of photons = \frac{Power}{Energy}[/tex]
From the question,
Power = 5 mW (milliwatts) = 5 × 10⁻³ W
Since 1 Watt = 1 Js⁻¹
Then, 5 × 10⁻³ W = 5 × 10⁻³ Js⁻¹
For the Energy,
As given from the question
Energy=(Power)x(time)
Time = 1 hour = (1 × 60 × 60) s = 3600 s
∴ Energy = 5 × 10⁻³ Js⁻¹ x 1 x 3600s
Energy =18.0 J
Now for the Number of photons produced,
[tex]Number of photons = \frac{Power}{Energy}[/tex]
Power = 5 × 10⁻³ Js⁻¹ = 0.005 Js⁻¹
[tex]Number of photons = \frac{0.005}{18}[/tex]
Number of photons = 2.78 × 10⁻⁴ Photons / sec
This is the number of photons produced in 1 second.
For the number of photons produced in 1 hour, we will multiply the result by 3600
(NOTE: 1 sec = [tex]\frac{1}{3600}[/tex] hour)
Number of photons = 2.78 × 10⁻⁴ Photons / sec
= 2.78 × 10⁻⁴ × 3600 Photons / hour
= 1.0008 Photons / hour
≅ 1 Photon / hour
Hence, the number of photons of light produced by the laser in 1 hour is
1 Photon / hour
1
Name two safety measures commonly used in electric circuits and
appliances
lectric
Answer:
always use insulated wire and use all the electrical appliances in proper way
"For the lowest harmonic of pipe with two open ends, how much of a wavelength fits into the pipe’s length?"
Answer:
0.5 lambda(wavelength)
Explanation:
We know that
The first harmonic for both side open ended pipe is
L= 1/2lambda
So L = 0.5*wavelength
Choose the box as the system of interest. What objects in the surroundings exert significant forces on this system
Answer:
Hello your question is incomplete attached below is the complete question
Your are lifting a heavy box we will consider this process for different choices of system and surroundings
Choose the box as the system of interest. What objects in the surroundings exert significant forces on this system
The floor the box you nonethe earthanswer : The earth and YOU
Explanation:
The objects that will exert significant force on this system would be the force exerted by the earth and force exerted by you
This is because the force exerted by the earth is an internal force and it can be calculated as : m*g ( mass of the object * acceleration due to gravity ) also the force exerted by you are force due to normal reaction when lifting a load
Any body moving with simple harmonic motion is being acted on by a force that is:__________.
a) proportional to a sine or cosine function of the displacement
b) directly proportional to the displacement
c) proportional to the inverse square of the displacement
d) constant
Answer:
B
Explanation:
Because this oscillations occur when the restoring force is directly proportional to displacement, given as
F=-kx
Where k= force constant
X= displacement
Does anybody know to solve this?
Answer:
25600 cm
2.56 x 10⁴ cm
Explanation:
Step 1: Find conversion
There are 100 cm in 1 m.
Step 2: Set up dimensional analysis
[tex]256m(\frac{100cm}{1 m} )[/tex]
Step 3: Multiply and cancel out units
25600 cm
2.56 x 10⁴ cm
A creature moves at a speed of 7.86 furlongs/fortnight (not a very common unit of speed). If 1.0 furlong = 220 yards 1 fortnight = 14 days 1 yard = 0.9144 meter and 1 day= 86400 sec find the speed of the creature (which is probably a snail).
1. 2.28745 × 109 m/s
2. 0.00130719 m/s
3. 1.16706 × 107 m/s
4. 47261.3 m/s
5. 0.25621 m/s
6. 39516.4 m/s
7. 5.29359 × 10−6 m/s
Answer:
2 0.00130719 m/s
Explanation:
Now we have
7.86 furlongs/fortnight
7.86 x 220 yards / fortnight
1729.2yards / fortnight
1647.8 yards / 14 days
123.5yards / day
So
123.5 x 0.9144 meter / day
112.meters / day
=112.9meters / 86400s
= 0.001307m/s
Four students measured the same line with a ruler like the one shown below. The results were as follows: 5.52 cm, 6.63 cm, 5.5, and 5.93. Even though you cannot see the line they actually measured, which of the recorded measurements are possible valid measurements for this instrument, according to its precision? Select all that apply. 1. 5.52 2. 6.63 3. 5.5 4. 5.93
Answer:
correct answer is 1 and 3
Explanation:
In direct measurement with an instrument, the precision or absolute error of the instrument is given by its appreciation, in this case we see that the measurements have two decimal places, so the appreciation of the instrument must be 0.01 cm
Based on this appreciation, the valid measurements are 5.52 and 5.5.
the other two measurements have errors much higher than the assessment of the instrument, for which there must have been some errors in the measurement.
The correct answer is 1 and 3
El tubo de entrada que suministra presión de aire para operar un gato hidráulico tiene 2 cm de diámetro. El pistón de salida es de 32 cm de diámetro. ¿Qué presión de aire se tendrá de aire se tendrá que usar para levantar un automóvil de 17,640 N?`
Answer:
La presión neumática para levantar un automóvil de 17,640 newtons es 220,500 pascales.
Explanation:
Asumiendo que la presión ([tex]P[/tex]), medida en pascales, tiene una distribución uniforme sobre la superficie del pistón, se calcula a partir de la siguiente expresion:
[tex]P = \frac{F}{A}[/tex]
Donde:
[tex]F[/tex] - Fuerza motriz, medida en newtons.
[tex]A[/tex] - Área del pistón, medida en metros cuadrados.
La fuerza motriz es equivalente al peso del automóvil. El área del pistón ([tex]A[/tex]), medido en metros cuadrados, es determinado por:
[tex]A=\frac{\pi}{4}\cdot D^{2}[/tex]
Donde [tex]D[/tex] es el diámetro del pistón, medido en metros.
Si [tex]D = 0.32\,m[/tex] y [tex]F =17,640\,N[/tex], entonces la presión neumática es:
[tex]A = \frac{\pi}{4}\cdot (0.32\,m)^{2}[/tex]
[tex]A \approx 0.080\,m^{2}[/tex]
[tex]P = \frac{17,640\,N}{0.080\,m^{2}}[/tex]
[tex]P = 220,500\,Pa[/tex]
La presión neumática para levantar un automóvil de 17,640 newtons es 220,500 pascales.
Which of the following statements is/are true for ultrasonic test?a. Equipment used for ultrasonic testing is portableb. Complicated shapes can be easily scannedc. Waves generated are health hazardousd. All the above statements are true
Answer:
Equipment used for ultrasonic testing is portable
Explanation:
An ultrasonic tester is used to detect flaws such as cracks and leaks. Hence, an ultrasonic tester is an integral tool used in material testing and engineering, manufacturing quality control, equipment condition monitoring, building and bridge inspection and much more.
Ultrasonic testing can be performed on steel and other metals and alloys, though it can also be used on concrete, wood and composites, although with less resolution.
In the park, there are 25 pigeons, 15 squirrels, 5 rabbits, and 5 stray cats. Why
can't you draw a line graph using only this information?
Answer: Line graph should be used to show how one variable changes over time not to show multiple categories or variables are at one specific point in time.
Explanation:
In maths, statistics, and related fields, graphs are used to visually display variables and their values. In the case of line graphs, these are mainly used to display evolution or change of a variable over time. For example, a line graph can show how the number of divorces changed from 1920 to 2010.
In this context, the number of different animals in the park cannot be represented through a line graph because this situation does not imply a variable changing over time. Moreover, this situation includes multiple variables or categories of animals and the data shows only one specific point in time, which can be better represented through a bar graph.
When you use a graduated cylinder in the lab, you can only use it to find the volume of liquids. (5 points)
True
False
Answer:
false
Explanation:
you can't only use it to find the volume of liquids
Unit 1 Horizontal Kinematics Homework #3 Acceleration 1. A bowling ball starts from rest and moves 300 m down the gutter in 22.4 seconds. a) What is its speed at the end of the track? b) What is its acceleration?
Answer:
Explanation:
since the object start its motion from rest and ends its motion at 300 m so
ΔS=S2-S1=300m-0m=300 m
given time is 22.4 sec therefore
v=ΔS/t
v=300/22.4=14.7 m/s
so the speed of the ball at the end of the track is 14.7 m/s
now to find the acceleration we know that
a=v/t
a=14.7/2.4
a=0.65m/sec²
An ion has a mass of 6.79 × 10-27 kg and a charge of +4e. What is the magnitude of the electric field that will balance the gravitational force on the particle?
Answer:
Explanation:
200.34
The aqueous humor in a person's eye is exerting a force of 0.242 N on the 1.21 cm2 area of the cornea. What pressure is this in mm Hg?
Answer:
15.00124mmHgExplanation:
Pressure is defined as the ratio of force applied to an object to its area.
Pressure = Force/Area
Given parameters
Force = 0.242N
Area = 1.21cm²
Required parameters
Pressure = 0.242/1.21
Pressure = 0.2N/cm²
Using the conversion to convert the pressure to mmHg
1N/cm² = 75.0062mmHg
0.2N/cm² = y
y = 0.2 * 75.0062
y = 15.00124mmHg
Hence the pressure in mmHg is 15.00124mmHg
An athlete needs to lose weight and decides to do it by “pumping iron.” (a) How many times must an 90.0 kg weight be lifted a distance of 0.890 m in order to burn off 1.00 lb of fat, assuming that that much fat is equivalent to 3500 kcal? (b) If the weight is lifted once every 2.10 s, how long does the task take?
Answer:
230kg would be the best answer
Explanation:
Calculate the location xcm of the center of mass of the Earth-Moon system. Use a coordinate system in which the center of the Earth is at x
Answer:
The center of mass of the Earth-Moon system is 4.673 kilometers away from center of Earth.
Explanation:
Let suppose that planet and satellite can be treated as particles. The masses of Earth and Moon ([tex]m_{E}[/tex], [tex]m_{M}[/tex]) are [tex]5.972\times 10^{24}\,kg[/tex] and [tex]7.349\times 10^{22}\,kg[/tex], respectively. The distance between centers is 384,403 kilometers. The location of the center of mass can be found by using weighted averages:
[tex]\bar x = \frac{x_{E}\cdot m_{E}+x_{M}\cdot m_{M}}{m_{E}+m_{M}}[/tex]
If [tex]x_{E} = 0\,km[/tex] and [tex]x_{M} = 384,403\,km[/tex], then:
[tex]\bar x = \frac{(0\,km)\cdot (5.972\times 10^{24}\,kg)+(384,403\,km)\cdot (7.349\times 10^{22}\,kg)}{5.972\times 10^{24}\,kg+7.349\times 10^{22}\,kg}[/tex]
[tex]\bar x = 4.673\,km[/tex]
The center of mass of the Earth-Moon system is 4.673 kilometers away from center of Earth.
A security guard walks at a steady pace, traveling 190 m in one trip around the perimeter of a building. It takes him 260 s to make this trip.what is his speed. express answer in 2 significant figures
Answer:
0.7 m/s
Explanation:
The following data were obtained from the question:
Distance travalled (d) = 190 m
Time (t) = 260 secs
Speed (S) =..?
Speed is simply defined as the distance travelled per unit time. Mathematically, it is expressed as:
Speed = Distance (d) /time(t)
S = d/t
With the above formula, we can calculate the speed of the security guard as follow:
Distance travalled (d) = 190 m
Time (t) = 260 secs
Speed (S) =..?
S = d/t
S = 190/260
S = 0.7 m/s
Therefore, the speed of the security guard is 0.7 m/s
A security guard walks at a steady pace, traveling 190 m in one trip around the perimeter of a building. The speed of the security guard is approximately 0.73 m/s.
Given:
Distance (d) = 190 m
Time (t) = 260 s
To calculate the speed of the security guard, we can use the formula:
Speed = Distance / Time
Speed = 190 / 260 = 0.73 m/s
Therefore, A security guard walks at a steady pace, traveling 190 m in one trip around the perimeter of a building. The speed of the security guard is approximately 0.73 m/s (rounded to two significant figures).
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The volume of a ball was measured at 500.0 cm3, and then mass was measured on this triple beam balance. What would be the most accurate reading for the mass of the ball?Using this mass, what would be the most accurate calculation of density for the ball? Round to the nearest ten thousandths.
Answer:
the answer is 0.8084
Explanation:
i just did it and got it correct
Consider position [x] = L, time [t] = T, velocity [v] = L/T and acceleration [a] = L/T 2 . Find the exponent A in the equation v = a^2 t^ A /x
Answer:
The exponent A in the equation is 3.
Explanation:
v = a^2 t^ A /x
[tex]v = \frac{a^2t^A}{x} \\\\vx = a^2t^A\\\\(\frac{L}{T})(L) = (\frac{L}{T^2})^2(T)^A\\\\ \frac{L^2}{T}= (\frac{L^2}{T^4})(T)^A\\\\ \frac{L^2}{T} *\frac{T^4}{L^2} = (T)^A\\\\T^3 = T^A\\\\\frac{T^3}{T^3} = \frac{T^A}{T^3}\\\\T^{3-3} = T^{A-3}\\\\3-3 = A-3\\\\0 = A-3\\\\A = 3[/tex]
Therefore, the exponent A in the equation is 3.
An agent has just listed a power plant. This is an example of what type of real estate?
Answer: industrial properties
Explanation:
The power plant listed by the agent falls under industrial property. An industria property is a property which is either used in manufacturing, rentage, warehousing, processing e.t.c.
in this case the plant Would be used in the generation of power which would be sold. so yes the property falls under the category
Light rays that are reflected twice inside a rain water droplet can produce a second-order rainbow. True False mim
Answer:
Yes
Explanation:
A 1000 kg elevator is accelerated upward at a rate of 0.70 m/s2. What is the tension in the cable pulling the elevator upward when it experiences this acceleration?
Answer:
[tex]\Huge \boxed{\mathrm{700 \ N}}[/tex]
Explanation:
Tension is the force exerted.
[tex]\sf Force \ (N) = mass \ (kg) \cdot acceleration \ (m/s^2)[/tex]
[tex]F=1000 \cdot 0.70[/tex]
[tex]F=700[/tex]
The tension in the cable is 700 N.
The tension of an body moving upward can be calculated from its weight and normal force. The tension in cable pulling with an acceleration of 0.7 m/s² is 10500 N.
What is tension?Tension is kind of force actually made by pulling a moving body. Like the force exerted by a cable, chain, string or a rope etc.
When an object gains potential energy with a restoring force if existing , then the restoring force will create a tension force. It is a transmitted force and can be calculated from the normal force acting.
It is given that the mass of the elevator is 1000 Kg, then its weight is mass multiplied by gravity of 9.8 m/s². Thus weight of the elevator is 1000 × 9.8 m/s² = 9800 N
The normal force is F = ma is calculated from the mass and acceleration as follows:
F = ma
= 1000 kg ×0.70 m/s²
= 700 N.
The tension force is the sum of weight of he body and the normal force,
Thus T = w + ma
T = 9800 N + 700 N
= 10500 N.
Therefore, tension in cable pulling with an acceleration of 0.7 m/s² is 10500 N.
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A worker is pushing a crate of tools up a ramp into a truck. The crate has a mass of 120 kg and is accelerating at a rate of 1.05 m/s^2. Once he finishes pushing that crate up, he then takes another crate that is 3 times as massive and pushes it up the ramp with an acceleration of 0.71 m/s^2. What is the ratio of the force the worker used on the on the 120 kg crate and the more massive crate?
Answer:
B) 0.493
Explanation:
First Crate
Formula: F=ma
120kg*1.05m/s^2= 126N
Second Crate
Formula: F=ma
3*120kg=360kg
360kg*0.71m/s^2=255.6
Find the ratio by dividing
120kg/255.6kg=0.4929
Round 0.4929=0.493
Hope this Helps!!
A 21.3 A current flows in a long, straight wire. Find the strength of the resulting magnetic field at a distance of 45.7 cm from the wire.
Answer:
The magnetic field strength due to current flowing in the wire is9.322 x 10⁻⁶ T.
Explanation:
Given;
electric current, I = 21.3 A
distance of the magnetic field from the wire, R = 45.7 cm = 0.457 m
The strength of the resulting magnetic field at the given distance is calculated as;
[tex]B = \frac{\mu_o I}{2\pi R}[/tex]
Where;
μ₀ is permeability of free space = 4π x 10⁻⁷ T.m/A
[tex]B = \frac{\mu_o I}{2\pi R}\\\\B = \frac{4\pi*10^{-7} *21.3}{2\pi(0.457)}\\\\B = 9.322 *10^{-6} \ T[/tex]
Therefore, the magnetic field strength due to current flowing in the wire is 9.322 x 10⁻⁶ T.
The pendulum consists of two slender rods AB and OC which have a mass of 3 kg/m. The thin plate has a mass of 12 kg/m2 . a) Determine the location ӯ of the center of mass G of the pendulum, then calculate the mass moment of inertia of the pendulum about z axis passing through G. b) Calculate the mass moment of inertia about z axis passing the rotation center O.
Answer:
The answer is below
Explanation:
a) The location ӯ of the center of mass G of the pendulum is given as:
[tex]y=\frac{0+(\pi*(0.3\ m) ^2*12kg/m^2*1.8\ m-\pi*(0.1\ m) ^2*12kg/m^2*1.8\ m)+0.75\ m*1.5\ m *3\ kg/m}{(\pi*(0.3\ m) ^2*12kg/m^2-\pi*(0.1\ m) ^2*12kg/m^2)+3\ kg/m^2*0.8\ m+3\ kg/m^2*1.5\ m} \\\\y=0.88\ m[/tex]
b) the mass moment of inertia about z axis passing the rotation center O is:
[tex]I_G=\frac{1}{12}*3(0.8)(0.8)^2+ 3(0.8)(0.888)^2-\frac{1}{2}*(12)(\pi)(0.1)^2(0.1)^2 -(12)(\pi)(0.1)^2(1.8-\\0.888)^2+\frac{1}{2}*(12)(\pi)(0.3)^2(0.3)^2 +(12)(\pi)(0.3)^2(1.8-0.888)^2+\frac{1}{12}*3(1.5)(1.5)^2+\\3(1.5)(0.888-0.75)^2\\\\I_G=13.4\ kgm^2[/tex]
c) The mass moment of inertia about z axis passing the rotation center O is:
[tex]I_o=\frac{1}{12}*3(0.8)(0.8)^2+ \frac{1}{3}* 3(1.5)(1.5)^2+\frac{1}{2}*(12)(\pi)(0.3)^2(0.3)^2 +(12)(\pi)(0.3)^2(1.8)^2-\\\frac{1}{2}*(12)(\pi)(0.1)^2(0.1)^2 -(12)(\pi)(0.1)^2(1.8)^2\\\\I_o=13.4\ kgm^2[/tex]
In which of these star groups would you mostly likely find the least heavy-element abundance for the stars within them: open clusters, globular clusters, or associations?
Answer: globular clusters
Explanation:
A globular cluster is a star which is usually spherical, it’s a collection of stars which is known to orbits a galactic core. Globular clusters are usually very tightly bound together by gravity, this helps in giving them their spherical shapes which they are known for, and it’s relatively high stellar densities which is found toward their centers.
You throw a 20-N rock vertically into the air from ground level. You observe that when it is a height 14.8m above the ground, it is traveling at a speed of 25.0 m/s upward.
A) Use the work-energy theorem to find its speed just as it left the ground. What is it?
B) Use the work-energy theorem to find its maximum height. What is it?
Answer:
(A) The speed just as it left the ground is 30.25 m/s
(B) The maximum height of the rock is 46.69 m
Explanation:
Given;
weight of rock, w = mg = 20 N
speed of the rock at 14.8 m, u = 25 m/s
(a) Apply work energy theorem to find its speed just as it left the ground
work = Δ kinetic energy
F x d = ¹/₂mv² - ¹/₂mu²
mg x d = ¹/₂m(v² - u²)
g x d = ¹/₂(v² - u²)
gd = ¹/₂(v² - u²)
2gd = v² - u²
v² = 2gd + u²
v² = 2(9.8)(14.8) + (25)²
v² = 915.05
v = √915.05
v = 30.25 m/s
B) Use the work-energy theorem to find its maximum height
the initial velocity of the rock = 30.25 m/s
at maximum height, the final velocity = 0
- mg x H = ¹/₂mv² - ¹/₂mu²
- mg x H = ¹/₂m(0) - ¹/₂mu²
- mg x H = - ¹/₂mu²
2g x H = u²
H = u² / 2g
H = (30.25)² / 2(9.8)
H = 46.69 m
Generator What does RPM stand for? What four things can you adjust to get the highest maximum voltage?
Answer:
revolution per minutes
Explanation:
increase number of turns on coil
increase speed
use of permanent magnet
increase in speed of object
RPM stands for revolution per minutes.
The four things you can adjust to get the highest maximum voltage are the number of turns of coil, the strength of the magnetic field, the area of the coil, and the angular frequency of the coil.
RPM stands for revolution per minutes; which describes the number of turns made by the coil in a single minute.
The induced voltage in the generator coil is calculated as follows;
[tex]E_{max} = NBA \omega[/tex]
where;
N is the number of turnsB is the strength of the magnetic fieldA is the area of the coilω is the angular frequencyThus, the four things you can adjust to get the highest maximum voltage are the number of turns of coil, the strength of the magnetic field, the area of the coil, and the angular frequency of the coil.
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What will be the force if the particle's charge is tripled and the electric field strength is halved? Give your answer in terms of F
Answer:
F' = (3/2)F
Explanation:
the formula for the electric field strength is given as follows:
E = F/q
where,
E = Electric Field Strength
F = Force due to the electric field
q = magnitude of charge experiencing the force
Therefore,
F = E q ---------------- equation (1)
Now, if we half the electric field strength and make the magnitude of charge triple its initial value. Then the force will become:
F' = (E/2)(3 q)
F' = (3/2)(E q)
using equation (1)
F' = (3/2)F
When the charge of the particle is tripled, and magnetic field strength is halved, the force increases by factor of 1.5 (1.5 F)
The force experienced by a particle placed in magnetic field is given as;
F = qvB
where;
q is the charge of the particlev is the velocity of the particleB is the magnetic field strengthWhen the charge of the particle is tripled, q₂ = 3q and magnetic field strength is halved, B₂ = 0.5B.
The magnetic force of the particle is determined as;
[tex]F = qvB\\\\ v = \frac{F}{qB} \\\\ \frac{F_1}{q_1B}_1 = \frac{F_2}{q_2B_2}\\\\ F_2 = \frac{F_1 q_2B_2}{q_1 B_1} \\\\ F_2 = \frac{F \times 3q_1\times 0.5B_1}{q_1B_1} \\\\ F_2 = 1.5 F[/tex]
Thus, when the charge of the particle is tripled, and magnetic field strength is halved, the force increases by factor of 1.5 (1.5 F).
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Alice drops a rock to a well. She hears the splash of the rock 4.1s later. The speed of sound is 340m/s. How deep is the well
Answer:
697 m
Explanation:
From the question above,
Note: Alice hears the splash of the rock in the well through the help of echo.
Applying,
v = 2x/t........................ Equation 1
Where v = speed of sound, x = depth of the well, t = time.
make x the subject of the formula in equation 1
x = vt/2................... Equation 2.
Given: v = 340 m/s, t = 4.1 s
Substitute these values into equation 2
x = 340(4.1)/2
x = 697 m.