Hi there!
We can first find the angular displacement of the first 20 seconds by finding the angular acceleration.
Begin by converting 120 rev/min to rev/sec:
120 rev/min × 1 min/60 sec = 2 rev/sec
ω = αt
2 = 20α
α = 0.1 rev/sec²
θ = ωit + 1/2αt²
The fan starts from rest, so:
θ = 1/2αt²
θ = 1/2(0.1)(20²) = 20 revolutions
Now, for the next 40 seconds, we can find the fan's deceleration:
ωf = ωi + αt
0 = 2 + αt
-2 = 40α
α = -0.05 rad/sec²
Use the above equation:
θ = ωit + 1/2αt²
θ = 2(40) + 1/2(-0.05)(40²) = 80 - 40 = 40 rev
θ = 4800 - 2400 = 2400 revolutions
Add the two:
θtotal = 20 + 40 = 60 revolutions
6. Two skaters, Jim (65 kg) and Mary (50 kg) are standing at rest on the ice. They push each other
and Mary recedes at 2.5 m/s towards the east. Find Jim's velocity (magnitude and direction).
Hi there!
This is an example of a recoil collision.
Let m1, v1 be Mary
Let m2, v2 be Jim
Utilize the conservation of momentum:
m1v1 + m2v2 = m1v1' + m2v2'
The initial velocities are zero (at rest), so:
0 = m1v1' + m2v2'
Let east be positive, so Jim recoils with a negative velocity:
0 = m1v1' - m2v2'
Set the two equal and solve:
m1v1' = m2v2'
m1v1'/m2 = v2'
(50)(2.5)/65 = v2' = 1.92 m/s to the WEST
Select the correct answer.
When rocks containing copper are oxidized, they tend to turn from red to green. Based on this information, what evidence
would best support the theory that oxidation could not have occurred in Earth's early atmosphere?
Rocks from early Earth that contained copper are green in color.
There are no copper-containing rocks from early Earth.
Rocks from early Earth that contained copper are red in color.
All copper minerals were converted to iron minerals.
Answer:
Rocks from early Earth that contained copper are red in color
Explanation:
"Copper, a red mineral, reacts with oxygen to form a green-colored compound. In early years, rocks containing copper were red. This fact shows that there was no oxygen in the early atmosphere to oxidize red copper into the green-colored compound."
Consider the dot diagrams for Objects A, B, and C. The arrow-
represents the direction of motion. Match the motion of
Objects A, B, and C to one of the lines on the graph.
Numbers can be used only one time.
A
2
B
Pos'n
3
С
-t
Tap
A matches graph:
B matches graph:
C matches graph:
4
5
6
--
Pos'n
t
Can anyone tell the answer
A sample of polonium-210 was left for 414 days.
BA
After this time it had a mass of 1.45 x 10^-4 g
The half-life of polonium-210 is 138 days.
Calculate the initial mass of the sample
Answer:
PO(1) = PO(0) / 2 1 refers to 1 half life of PO(0)
PO(2) = PO(1) / 2 = P(0) / 4 amount of PO left after 2 half-lives
PO(3) = PO(2) / 2 = PO(0) / 8 amount of PO left after 3 half-lives
414 da / 138 da = 3 3 half-lives pass in 414 da
PO(0) = 8 PO(3) = 8 * 1.45E-4 g = 1.16E-3 g = .00116 g after 414 days
A tellurium-sapphire laser can produce light at wavelength of 800 nm in ultrashort pulses that last only 4.00x10-15s (4.00 femtoseconds, or 4.00 fs). The energy in a single pulse produced by one such laser is 2.00 μJ = 2.00x10-6 J, and the pulses propagate in the positive x-direction. Find a) the frequency of the light; b) the energy and minimum energy uncertainty of a single photon in the pulse
The speed of light and the propagation of errors allows to find the results on the questions of the radiation emitted by the laser are:
a) The frequency is: f = 3.7 10¹⁴ Hz
b) The energy with its uncertainty is: E = (2.465 ± 0.004) 10⁻¹⁹ J
a) The speed of a wave is related to its wavelength and frequency.
c = λ f
[tex]f = \frac{c}{\lambda}[/tex]
Where c is the speed of light, λ the wavelength and f the frequency.
They indicate that the wavelength is λ = 800 nm = 800 10⁻⁹ m, the speed of light is a constant c = 2.99 10⁸ m/s.
f = [tex]\frac{2.99 \ 10^8}{800 \ 10^{-9}}[/tex]
F = 3.7 10¹⁴ Hz
b) Planck's equation states that the energy is proportional to the frequency of the radiation.
E = h f
Where E is the energy, h the Planck constant and f the frequency.
E = 6.63 10⁻³⁴ 3.7 10¹⁴
E = 2.46467 10⁻¹⁹ J
The uncertainty or error is the fluctuation that a magnitude may have due to the precision in the measurements, when the magnitude is calculated by some formula, the propagation of these uncertainties must be carried out.
Δm = ∑ [tex]\sum \frac{dm}{dx_i} | \Delta x_I|[/tex]
the expression for energy is:
E = [tex]\frac{hc}{\lambda }[/tex]
[tex]\Delta E = \frac{dE}{d \lambda} |D\lambda |[/tex]
[tex]\Delta E = \frac{h c }{\lambda^2 } |\Delta \lambda |[/tex]
When the error in the measured magnitude is not explicitly indicated, we assume that the error is in the last digit written, therefore
Δλ = ± 1 nm = ± 1 10⁻⁹ m
We calculate.
[tex]\Delta E = \frac{6.63 \ 10^{-34} \ 2.99 \ 10^8 }{(800 \ 10^{-9})^2} 1 \ 10^{-9}[/tex]
ΔE = 3.1 10⁻²² J
the error is given with a significant figure.
ΔE = 3 10⁻²² J = 0.004 10⁻¹⁹ J
The result of the energy is:
E = (2.465 ± 0.004) 10⁻¹⁹ J
In conclusion, using the speed of light and the propagation of errors, we can find the results on the questions of the radiation emitted by the laser are:
a) The frequency is; f = 3.7 1014 Hz
b) The energy with its uncertainty is: E = (2.465 ± 0.004) 10⁻¹⁹ J
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a force acting on 25kg mass produces an acceleration of 4m/square what would this the same force produce on a 12kg mass
Answer:8.3m/s
Explanation:
from F=ma, f=25*4=100N. since the force is 100, 100=12a. acceleration= 8.3m/s
Managers use information systems to help them make decisions that will improve their businesses. What three levels of information do managers need to make these decisions? Provide one example of how information systems can provide this data.
The main categories of information systems include management-level system, operational-level system, and strategic-level system.
Information system simply means the integrated set of components that are vital for the collection, storage, and processing of data to make organizational decisions.
Information systems can be used at operational level in order to provide data that can support operational activities by keeping track of the transactions of the company.
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What torque will increase angular velocity of a solid cylinder of mass 16 kg and diameter 1 m from zero to 120 rpm in 8 s?
a)π/4Nm
b)π/2Nm
c)π/3Nm
d)πNm
how much of the light that reaches the earth from the sun is used for photosynthesis
Answer:
Less than one percent of the total energy that reaches Earth is used by plants for photosynthesis
A 45 kg object has a momentum of 255 kg m/s northward.What is the objects velocity
Answer:
5.66 m/s
Explanation:
p=mv
255 = 45v
v = 255/45
v = 5.66 m/s
If you want to verify your answer, just insert your value to the equation.
you moved from the top bunk of a bunk bed to the bottom and noticed that the air is colder. the cold air stays at the bottom because of
Answer:
heat transfer? sorry if I'm wrong!
A boy drops a stone in a well and finds it takes 2.60 seconds to hit the water.
A) How deep is the well?
B) With what speed does the stone hit the water?
Answer:
(i) How deep is the well (Height)
=> t = √(2H/g)
=> √2H = t × g
=> 2H = t² × g²
=> 2H = (2.60)² × (10)²
=> 2H = 6.76 × 100
=> 2H = 676
=> H = 676 ÷ 2
=> H = 338 m
(ii) speed of the stone:
=> v = √(2Hg)
=> v = √(2 × 338 × 10)
=> v = √6760
=> v = 26√10 m/s
A 455 kg cannon fires a 21 kg cannonball at 26 m/s. If the cannon is on wheels, at what velocity does it move backward?
Answer:
A cannon ball of mass 4.0 kg is fired from a stationary 96 kg cannon at 120 m/s. Calculate the velocity of the cannon immediately after firing.
total momentum of cannon and cannon ball before = 0 kg m/s - because neither object is moving
total momentum of cannon and cannon ball after collision = 0 kg m/s - because momentum is conserved
Momentum of cannon ball after firing = 4.0 × 120 = 480 kg m/s.
Momentum of cannon after firing = -480 kg m/s (because it recoils in the opposite direction and 480 - 480 = 0 kg m/s, the total momentum after collision).
Rearrange p = m v to find v:
v = p/m
v = 480 divided by 96
v = 5.0 m/s
Note that the forward velocity of the cannon ball was given a positive value. The negative value for the cannon's velocity shows that it moved in the opposite direction.
The total power input to the leaf blower is 750 W. The useful power outlet of the leaf blower is 360 W. Calculate the efficiency of the leaf blower.
H = Pu / P x 100% = 360/750 x 100% = 48%
P/s: Pu is the useful power outlet of the leaf blower
P is the total power input to the leaf blower
ok done. Thank to me :>
A science student observes three lines in an emission spectrum, one red, one yellow, and one blue. Which one was caused by an electron jumping the shortest distance
The transition that produced red light was caused by an electron jumping the shortest distance.
Visible light is made up of seven wavelengths the magnitude of the wavelength of a transition reflects the energy associated with such transition. The longer the wavelength shorter the transition that produced it.
Given that three lines in the visible spectrum produced three lines as follows;
Red - 625 - 740 nm
Yellow - 565 - 590 nm
Blue - 445 - 520 nm
We can see that the longest wavelength corresponds to red light hence it was caused by an electron jumping the shortest distance.
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1 =
Q=240c
t=300s
Please explain Im so confused
Answer:
Answer:
0.8 A
Explanation:
Given: Q = 240 C
t = 300 s
Required: I
Equation: I = Q / t
Solution: I = 240 C / 300 s
Answer: I = 0.8 A
what do you mean by frequency of sound is 50Hz
Answer:
This means the source of sound vibrates 50 times in one second. Therefore, number of vibrations in 1 minute, i.e. in 60 seconds = 50 x 60 = 3000 times.
Explanation:
An element with a force of 0.00SN moves at a minimum: 0.2m / s². Calculate the mass of that element.
Please find attached photograph for your answer.
Hope it helps.
Do comment if you have any query.
Seismic waves do not travel along the Earth’s surface.
Please select the best answer from the choices provided
T (true)
F (false)
Both choices are correct.
Some seismic waves travel along the Earth's surface.
Others don't.
Answer:
False
Explanation:
Edge2022
help please please please please
Answer:
lol can u tell what to help u with. cause I didn't understood
a cork floating in a beaker of water is attached to a spring, and the spring is attached to the bottom of the beaker. the spring pulls the cork farther below the water than it would be if it were just floating. what happens when we drop the beaker off a tall building?
Answer:
If we drop the beaker, due to inertia, the Cork will move upwards.
Option B is correct.
Explanation:
When we drop the beaker off a tall building, the cork attached to the spring moves in an upward direction.
What is spring force?Spring can be defined as a tool used for many purposes and its inertia is neglected by considering it is massless. When a spring is strained, undergoes displacement when it is compacted spring gets compressed but it can freely come to its equilibrium position.
Spring exerts an equal and an opposite force on a body that stretches or compresses it.
The Spring force formula can be written as:
F = k(x – x₀)
Where the spring force is F, xo is the equilibrium position, x is the displacement of the spring from the equilibrium position and the spring constant is k.
The negative sign shows that the spring force is a restoring force that acts in the opposite direction.
Therefore, the cork attached to the spring moves up when we drop the beaker off a tall building.
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Which of the following, if eliminated, would completely prevent the greenhouse effect from occurring on earth?
A. Atmosphere Clouds
B. Fossil fuels
C. Acid rain
D. The ozone layer
E. Chlorofluorocarbons
Chlorofluorocarbons is eliminated, would completely prevent the greenhouse effect from occurring on earth.
What is greenhouse effect?The greenhouse effect is a phenomenon in which heat from a planet's host star passes through its atmosphere and warms the surface of the planet, but greenhouse gases in the atmosphere prevent part of the heat from going directly to space, making the world warmer.
Chlorofluorocarbons gas is main cause of greenhouse effect so when we remove it from atmosphere than green house effect will be reduced.
Chlorofluorocarbons is eliminated, would completely prevent the greenhouse effect from occurring on earth.
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The following diagram shows a person exerting a
300.-newton force on the handle of a shovel that
makes an angle of 60. with the horizontal ground.
Determine the magnitude of the component of the
force perpendicular to the ground.
Answer:
260 Newtons
Explanation:
Okay, so what you have to do is know what the question is asking. It wants to know the force perpendicular to the ground. We know perpendicular makes a right angle, so we use the diagram to make it into a right triangle with a degree of 60, and hypotunese of 300 newtons. Now, we use basic trigonometry, we place x on the horizontal side since it perpendicular to the ground. We know it´s sin because x is opposite to 300 which is the hyp.
Sin= opp/hyp
x/300
sin(60)= x/300
300*sin(60)= 259.8, which rounds to
260 Newtons
There is your answer :D. Happy to help.
The component of the force which is perpendicular to the ground is → F [y] = 261 a[y].
What are the components of a Vector?A vector V making an angle θ with the x - axis, can be resolved into two two components along the x and y - axes respectively as →
V = Vcosθ a[x] + Vsinθ a[y]
where -
a[x] is the unit vector along the +x axis
a[y] is the unit vector along the +y axis.
Given is a force of magnitude 300 N acting on the handle that makes an angle of 60° with the horizontal ground.
The component normal to the ground will be the component along the y - axis. The component along the y - axis is the sine component. Suppose that vector F represents the force of magnitude (|F|) 300 N. The component perpendicular to the ground will be -
F [y] = |F| sinθ a[y]
F [y] = 300 x sin(60°) a[y]
F [y] = 300 x 0.87
F [y] = 261 a[y]
Therefore, the component of the force which is perpendicular to the ground is → F [y] = 261 a[y].
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The trachea splits into two branches called larynx true or false
pls answer somebodyyyyyyy
Answer:
False
Explanation:
The trachea divides into left and right air tubes called bronchi, which connect to the lungs. Within the lungs, the bronchi branch into smaller bronchi and even smaller tubes called bronchioles.
Hope this helps :)
Which type of wave requires a medium?
A. Light wave
B. Electromagnetic wave
C. Sound wave
D. Ultraviolet wave
The correct answer is option C. Sound wave
A sound wave is an example of a mechanical wave which requires a medium.
Answer:
The closest is “A”, however an ocean wave is not truly a transverse wave. It belongs to the category “gravity wave” (note: NOT gravitational wave as in cosmology) and occur at the interface between two media. In the case of a wave on the ocean surface it is specifically called a “surface gravity wave” . The particles in a surface gravity wave move in an oscillatory circular motion called the wave orbit not in a back and forth motion.
A ball is thrown at an angle of 38 degrees to the horizontal. What happens to the magnitude of the ball's vertical acceleration during the total time interval that the ball is in the air
Answer:
I belive it is 38 degrees
Explanation:
The magnitude of the vertical acceleration of the ball during the total time interval that the ball is in the air, the acceleration remains the same.
What is projectile motion?A projectile can be defined as an object that is in flight after being projected. The acceleration acting in the vertical direction which is because of gravity in a projectile motion. Therefore, we can apply the equations of motion separately on X-axis and Y-axis to find the parameters.
If any projectile is projected with the velocity 'v' and is making an angle θ from horizontal. The horizontal component of the initial velocity of the projectile will be equal to vcosθ.
The vertical component of the initial velocity of the projectile is v sinθ. The horizontal component remains the same as no acceleration is acting horizontally.
The ball will experience only one force which is gravity if there is no air resistance. The gravity remains constant if there is no initial speed of the ball. The acceleration of the ball will be in the downward direction and stays constant.
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The magnetic field of a straight, current-carrying wire is:
What do you notice about the lines of earthquakes and volcanoes and where they seem to occur on Earth's surface?
Answer:
Most earthquakes and volcanoes occur because of the movement of the plates, especially as plates interact at their edges or boundaries.
Explanation:
A race car is traveling at a speed of 80. 0 m/s on a circular racetrack of radius 450 m. What is it's centripetal acceleration in m/s2?.
Answer:
14.2m/s^2
Explanation:
The centripetal acceleration of the race car is 14.22 m/s².
What is centripetal acceleration?Centripetal acceleration is a characteristic of an object's motion along a circular path. Centripetal acceleration applies to any item travelling in a circle with an acceleration vector pointing in the direction of the circle's center.
In your daily existence, you must have encountered numerous instances of centripetal acceleration. A centripetal acceleration occurs when you drive in a circle, and a centripetal acceleration also occurs when a satellite orbits the earth. Centripetal refers to being in the center.
Given that: Speed of the race car: v = 80.0 meter/second.
Radius of the racetrack: r = 450 meter.
Hence, the centripetal acceleration of the car is = v²/r
= (80.0)²/450 m/s²
= 14.22 m/s².
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