Answer:
a) the period of vibration of the bird’s wings is 0.0667s
b) the frequency of the wings’ vibration is 15 Hz
c) the angular frequency of the bird’s wingbeats is 94.2 rad/s
Explanation:
Given the data in the question;
beat at a rate of up to 900 times per minute.
The number of vibrations per unit time can be be determined as follows;
frequency f = number of vibration / time ---------- let this be equation 1
Also Time period T is;
T = 1/f { time period and frequency are reciprocal to each other }
T = 1/f ---------- Let this be equation 2
Then, the angular frequency ω can be determined using the formular;
ω = 2π × f -------------- Let this be equation 3.
Now, given that; The wings of the blue-throated hummingbird beat at a rate of up to 900 times per minute; Hence,
from equation 1, frequency f = number of vibration / time
f = 900 / 1 min
f = 900 / 60 sec
f = 15 Hz
Therefore, the frequency of the wings’ vibration is 15 Hz
a) the period of vibration of the bird’s wings
from equation 2, T = 1/f ,
we substitute in the value of f
T = 1 / 15 Hz
T = 0.0667s
Therefore, the period of vibration of the bird’s wings is 0.0667s
c) the angular frequency of the bird’s wingbeats;
from equation 3, ω = 2π × f
we substitute
ω = 2π × 15 Hz
ω = 94.2 rad/s
Therefore, the angular frequency of the bird’s wingbeats is 94.2 rad/s
explain why the lamp does not light when the input to the transformer is directed current
Answer:
Direct current(DC) has no time varying field because current is constant as well as there is no relatively motion between coil and core(magnetic circuit) of the transformer. So there is no induced emf in secondary coil of the transformer. Tom Mounts, field engineer, and electronics technician.
Explanation:
can i have brainly if right
When two objects are at the same temperature we say they are at
Answer:
equal temperatures
Explanation:
When 1.5 kg of mass turns into energy, how much energy is released? Find the equation, substitution, and number with units.
Explanation:
[tex]from \: einstein \: equation : \\ E = m {c}^{2} \\ E = 1.5 \times {(3 \times {10}^{8} )}^{2} \\ E = 1.35 \times {10}^{17} \: joules[/tex]
A 300-g chunk of ice (of density 0.900 g/cm3) is placed in a water bucket. A 20.0-g rock, with a volume of 2.00 cm3, is placed on top of the ice before water is filled to the top. When the ice melts and the rock drops to the bottom of the buckt, how much water spills out or needs to be added to maintain full level? Ignore the possible dependence of the densities of ice and water on temperature.
Answer:
18 cm³ of water
Explanation:
The correct procedure and explanation is in the picture attached. If you have any doubts, feel free to leave in the comments.
Hope this helps
Describe the formation of galaxies.
Today's cosmologists assume that matter was not uniformly distributed in the universe after the Big Bang. Dense places attract more matter than the surrounding area according to their gravitational forces. Over the course of billions of years, these gas agglomerations eventually led to the formation of the galaxies we see today.
how hot can the desert get
Answer:
134 f
Explanation:
The hottest temperature ever reliably measured in a desert was 134 degrees F, in Death Valley of the Mojave Desert in 1913.
Temperature. During the day, desert temperatures rise to an average of 38°C (a little over 100°F). At night, desert temperatures fall to an average of -3.9°C (about 25°F). At night, desert temperatures fall to an average of -3.9 degrees celsius (about 25 degrees fahrenheit).
Desert surfaces receive a little more than twice the solar radiation received by humid regions and lose almost twice as much heat at night. Many mean annual temperatures range from 20-25 degrees Celsius. The extreme maximum ranges from 43.5-49 degrees Celsius. Minimum temperatures sometimes drop to -18 degrees Celsius.
which one hurry i need help pls dont get me wrong ..
Answer:
OPEN
Explanation:
An intentionally open circuit would be the circuit to the lights in the room that are turned off. There is no closed path available for the electricity to flow to the lights because the switch is in the "off" position which "opens" the path the electricity would normally flow through.
An object of mass 25kg is falling from the height h=10 m. calculate
a. The total energy of an object at h=10m.
b. Potential energy of the object when it is at h= 4m
c. Kinetic energy of the object when it is at h= 4m
d. What will be the speed of the object when it hits the ground?
Answer:
a=2500J,b=1000K,c=1000J,d=14.142m/s
Explanation:
V²=U²+2gh
V²=0 + 2×10×10=200m/s
a).kinetic energy=(1/2)mv²=(1/2)25×200=2500
potential energy=mgh
p.e=25×10×10=2500J
pe+ke=2500+2500=5KJ
b).mgh=25×10×4=1000J
c). V²=U²+2gh
V²=0+2×10×4
V²=80
kinetic energy=(1/2)mv²
=(1/2)25×80
=1KJ
d). From my first paragraph V²=200
V=√200
V=14.142m/s
Explain how newtons first law applies to the image to the left.
Magnesium hydroxide is a common ___?
Answer:
Hello There!!
Explanation:
The answer is=> It is a common component of antacids.
hope this helps,have a great day!!
~Pinky~
Which of the following is a problem with the estimated age of the universe?
There are stars in our galaxy that appear to be over 15 billion years old.
The universe is shrinking, which makes it is impossible to tell how old it is.
There should be more supergiants if the universe is really about ten billion years old.
There are planets in other galaxies that are less than five billion years old.
Answer:
There are stars in our galaxy that appear to be over 15 billion years old.
Explanation:
The age of the universe is the time past since the big ban event as based on observations of the early state of the universe. The comic problem with the universe is that it's estimated to be older since the time of the big bang. It also represents a contrast with objects in the galaxies such as stars, planets that could not have been present.A bat emits a sound at a frequency of 30.0 kHz as it approaches a wall. The bat detects beats such that the frequency of the echo is 900 Hz higher than the frequency the bat is emitting. The speed of sound in air is 340 m/s at emits a sound at a frequency of 30.0 kHz
(a) What is the speed of the bat?
(b) What is the wavelength of the sound that the bat hears15?
Answer:
a) the speed of the bat is 5.02 m/s
b) the wavelength of the sound that the bat hears is 0.011 m
Explanation:
Given the data in the question;
Frequency of sound emitted by a bat f = 30.0 kHz = 30000 Hz
detected frequency by the bat δf = 900 Hz
speed of sound in air c = 340 m/s
Let speed of sound and speed of bat be c and [tex]v_s[/tex] respectively;
Now, frequency of the sound that is coming from the bat towards the wall due to DROPPLER EFFET will be;
f₁ = ( c / ( c - [tex]v_s[/tex] ) )f ----- let this be equ 1
Also, frequency does not change after deflection. The bat becomes an observer as the dropper is shifted because the reflected sound wave is coming towards it;
Hence, Doppler shifted frequency will be;
f₂ = ( (c + [tex]v_s[/tex] ) / c )f₁
from equ 1, f₁ = ( c / ( c - [tex]v_s[/tex] ) )f, so we substitute
f₂ = ( (c + [tex]v_s[/tex] ) / c ) × ( c / ( c - [tex]v_s[/tex] ) )f
f₂ = ( (c + [tex]v_s[/tex] ) / ( c - [tex]v_s[/tex] ) )f
∴ beat frequency will be;
δf = f₂ - f = ( (c + [tex]v_s[/tex] ) / ( c - [tex]v_s[/tex] ) )f - f
δf = ( 2[tex]v_s[/tex] / c - [tex]v_s[/tex] )f
δf = ( 2[tex]v_s[/tex] / c - [tex]v_s[/tex] )f
2f/δf = c - [tex]v_s[/tex] / [tex]v_s[/tex]
2f/δf = c/[tex]v_s[/tex] - [tex]v_s[/tex] / [tex]v_s[/tex]
2f/δf = c/[tex]v_s[/tex] - 1
c/[tex]v_s[/tex] = 2f/δf + 1
[tex]v_s[/tex] = c / (2f/δf + 1)
now, we substitute in our values;
[tex]v_s[/tex] = 340 / ((2×30000 / 900 ) + 1)
[tex]v_s[/tex] = 340 / (66.6666 + 1)
[tex]v_s[/tex] = 340 / 67.6666
[tex]v_s[/tex] = 5.02 m/s
Therefore, the speed of the bat is 5.02 m/s
b) the wavelength of the sound that the bat hears
frequency of reflected wave is;
f₂ = f + δf = 30000 + 900 = 30900 Hz
λ₂ = c / f₂
we substitute
λ₂ = 340 / 30900
λ₂ = 0.011 m
Therefore, the wavelength of the sound that the bat hears is 0.011 m
5. A ball weighing 10 kg rolls 200 m down a frictionless incline with a 50 degree angle to the horizontal. If the ball’s initial velocity was 0 m/s, how much does the mechanical energy of the system change by the time the ball reaches its destination? A) It increased by 12%. B) It increases by 58%. C) It decreases by 12%. D) It does not change.
Answer:
D) It does not change
Explanation:
Since there is no friction in the inclined plane. Therefore, there is no loss in the total mechanical energy of the system. So according to the law of conservation of energy we can write:
Total Mechanical Energy at Start = Total Mechanical Energy at End + Frictional Loss
Total Mechanical Energy at Start = Total Mechanical Energy at End + 0
Total Mechanical Energy at Start = Total Mechanical Energy at End
It means there is no change in the total mechanical energy of the system.
Therefore, the correct option is:
D) It does not change
Which is one way to determine whether a reaction was a chemical reaction or a nuclear reaction?
Answer:
Check how much energy was released during the reaction or check for a change in total mass
If a body of mass 2 kg is moving with a velocity of 30 m/s, then
on doubling its velocity the momentum becomes
a 30 kgm/s
b 90 kgm/s
C 120 kgm/s
d 60 kgm/s
HALPLPLPPLL
Answer:
d. 60
Explanation:
If a body of mass 2 kg is moving with a velocity of 30 m/s, then
on doubling its velocity the momentum becomes
a 30 kgm/s
b 90 kgm/s
C 120 kgm/s
d 60 kgm/s
HALPLPLPPLL
Answer:
120
Explanation:
A box has base dimensions of 30 cm x 30 cm and a mass of 3 kg. Calculate to what
depth it sinks when placed in a tank of water (assume the sides are sufficiently high,
so that it floats). Density of water = 1000 kgm-3. Assume g=10 ms-2 for this problem.
Answer:
60
Explanation:
A box has base dimensions of 30 cm x 30 cm and a mass of 3 kg. Calculate to what
depth it sinks when placed in a tank of water (assume the sides are sufficiently high,
so that it floats). Density of water = 1000 kgm-3. Assume g=10 ms-2 for this problem.
Based on the number on the fuse, what do you think is the maximum current allowed in this circuit?
Answer:
0.3 A
Explanation:
Build the circuit attached. Make sure the switch is turned off as you build the circuit. Set the Selected battery voltage to 10 volts.
A. Based on the number on the fuse, what do you think is the maximum current allowed in this circuit?
Solution:
A fuse is a safety device which is used in circuits for preventing very high currents which can cause overloading or start a fire. A fuse is made up of a low resistance thin piece of metal such that the flow of high current can cause the metal to melt leading to an open circuit. A fuse lets current flow up to a maximum value before it melts and the circuit will be broken.
From the image attached, since the maximum rating of the fuse is 0.3 A, hence the maximum current that can flow through the circuit is 0.3 A.
Question 1
2 pts
Explain what causes a solution to be a strong acid.
Answer:
Cuanto más fuerte es el ácido, más rápido se disocia para generar H +start superscript, plus, end superscript. Por ejemplo, el ácido clorhídrico (HCl) se disocia completamente en iones hidrógeno y cloruro cuando se mezcla con agua, por lo que se considera un ácido fuerte.
Aluminium is produced by the reduction of aluminium oxide
What is meant by the term reduction?
Answer:
Explanation:The word reduction in terms of chemistry means loss of Oxygen,Gain of hydrogen,Gain of electrons and loss of oxidation state.
Please mark me as brainiest.
Aluminium is extracted from aluminium oxide by electrolytic reduction.
What is reduction?The process is termed as a reduction if
there is a loss of oxygen or an electronegative atom.there is a gain of hydrogen or an electropositive atom.loss of electrons.decrease in oxidation number.What is electrolytic reduction?The electrolysis method used to obtain metals from molten chloride or oxides is known as electrolytic reduction.
What is the use of electrolytic reduction?It is used in the extraction of highly electropositive metals.
To learn more about reduction and electrons here,
https://brainly.com/question/14698511
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Imagine you could travel to the moon where the acceleration due to gravity is 1.6 m/s^2. What would be the period of
a pendulum that is 1.0 m?
Show your work.
Answer:
4.9612 s
Explanation:
Applying,
T = 2π√(L/g)............... Equation 1
Where T = period of the pendulum, L = Lenght of the pendulum, g = acceleration due to gravity of the moon, π = pie.
From the question,
Given: L = 1 m, g = 1.6 m/s²
Constant: π = 3.14
Substitute these values into equation 1
T = 2×3.14×√(1/1.6)
T = 6.28√(0.625)
T = 6.28×0.79
T = 4.9612 s
what are conductors and insulators
HURRY ILL GIVE 15 POINTS
Carla draws two circuit diagrams that connect the same components in different ways as shown which statement about the circuit is correct?
Circuit A is correct
In a single-slit experiment, the slit width is 150 times the wavelength of the light.
What is the width (in mm) of the central maximum on a screen 2.6 m behind the slit?
I have tried:
y=[(1+1/2)(lambda)(2.6m)] / (150lambda)
to bring me to
y=[(1.5)(2.6)] \ (150)
giving me a y value in mm of 26
So this helicopter pilot dropped me in the middle of an absolutely smooth frictionless
lake. He thought it was really funny. The only thing the pilot let me take is a bowling
ball. I tried to claw my way to the shore but was unable to get any horizontal force on
the super slippery zero friction ice. Explain how I can get to shore and why it will
work before I freeze to death. This test is about momentum. I wonder if my solution
has anything to do with that ...
The FitnessGram™ Pacer Test is a multistage aerobic capacity test that progressively gets more difficult as it continues. The 20 meter pacer test will begin in 30 seconds. Line up at the start. The running speed starts slowly, but gets faster each minute after you hear this signal. [beep] A single lap should be completed each time you hear this sound. [ding] Remember to run in a straight line, and run as long as possible. The second time you fail to complete a lap before the sound, your test is over. The test will begin on the word start. On your mark, get ready, start.
40 points! Will give brainliest!
Which of the following describes an advantage of AC electricity over DC electricity?
A) AC is found in most low voltage operations.
B) AC is provided as strong, short bursts of electricity.
C) AC can be transported over long distances.
D) AC can be used is small electronic devices.
1. How would the forces from a header with such a light soccer ball cause a concussion? Draw
Two free body diagrams showing how the amount of peak force on the head would compare
to the amount of peak force on a soccer ball in a header that causes a collision.
Answer:
soccer when the ball hits an unprepared player in the head. He also gave examples of concussions occurring when players accidentally knock their heads into other players while attempting to head the ball, particularly if they are attempting to flick the ball backwards.
Explanation:
Heading in soccer can increase your risk of concussions. Over time, repeated subconcussive injuries can also accumulate and cause brain damage.
NASA is giving serious consideration to the concept of solar sailing. A solar sailcraft uses a large, lowmass sail and the energy and momentum of sunlight for propulsion.
a. Should the sail be absorbing or reflective? Why?
b. The total power output of the sun is 3.9×10^26W. How large a sail is necessary to propel a 10,000-kg spacecraft against the gravitational force of the sun? Express your result in square kilometers.
c. Explain why your answer to part (b) is independent of the distance from the sun.
Answer:
a) the reflective surface has twice the energy transfer
b) A = 1.3 10²⁷ km²
c) the energy emitted by the sun is distributed in a sphere that depends on the square of the distance, and the gravitational force depends on the square of the distance
Explanation:
a) The pressure exerted on the candle is related to the variation of the momentum
P = [tex]\frac{1}{c} \ \frac{dp}{dt}[/tex]
in a case of absorption (inelastic shock) all the energy is absorbed therefore the pressure is
P = \frac{1}{c} \ \frac{dp}{dt}
in the case of reflection (elastic shock) an energy is absorbed by absorbing the light and then by action and reaction the same energy is absorbed in the reflected light
P = 2 \frac{1}{c} \ \frac{dp}{dt}
In conclusion, the reflective surface has twice the energy transfer.
b) pressure is defined with force per unit area
P = F / A
F = P A
this force must be greater than the gravitational force of attraction of the sun
Fg = G m Ms / r²
let's look for the case that the two forces are equal
F = Fg
P A_sail = G m Ms = r²
suppose a fully reflective sail
[tex]2 \frac{S}{c} \ A_{sail} = G \frac{m M_s}{r^2}[/tex]
The pointing vector is the power delivered per unit area
S = I = P / A
where A is the area of the sphere where the is distributed by the sun
A = 4π r²
we substitute
[tex]\frac{2P}{c} \ \frac{A_{sail}}{4 \pi r^2} = G \frac{m M_s}{r^2}[/tex]
[tex]\frac{1}{2 \pi \ c }[/tex] A_{sail} = G m M_s
A = G m M_s 2π c
let's calculate
A = 6.67 10⁻¹¹ 10000 2 10³⁰ 2π 3 10⁸
A = 1,257 10³³ m²
let's reduce to km²
A = 1.3 10³³ m² (1km / 10³ m) ²
A = 1.3 10²⁷ km²
c) The size of the candle is independent of the distance to the sun because the energy emitted by the sun is distributed in a sphere that depends on the square of the distance, and the gravitational force depends on the square of the distance, therefore the two dependencies are canceled.
A loudspeaker, mounted on a tall pole, is engineered to emit 75% of its sound energy into the forward hemisphere, 25% toward the back. You measure an 85 dB sound intensity level when standing 3.5 m in front of and 2.5 m below the speaker. What is the speaker’s power output?
Answer:
"0.049 W" is the correct answer.
Explanation:
According to the given question,
[tex]r = \sqrt{(3.5)^2+(2.5)^2}[/tex]
[tex]=\sqrt{8.5}[/tex]
[tex]SL=85[/tex]
As we know,
⇒ [tex]SL=10 \ log(\frac{I}{I_o} )[/tex]
[tex]85=10 \ log(\frac{I}{10^{-12}} )[/tex]
[tex]I=3.162\times 1^{-4} \ W/m^2[/tex]
Now,
⇒ [tex]P_{front} = I(2\pi r^2)[/tex]
[tex]=(3.162\times 10^{-4})(2\pi\times 18.5)[/tex]
[tex]=0.0368 \ W[/tex]
[tex]=0.75 \ P[/tex]
or,
[tex]=0.049 \ W[/tex]
A series circuit is set up with an AA battery along with an mystery material and ammeter; however, there’s no current passing through.
A.Insulator
B.Conductor
C.Semiconductor
Answer:
A. Insulator
Explanation:
Since there is no current passing through at all.
What is the speed of the wave above of the frequency is 7.0 hertz
Answer:
Umm
Explanation: