Answer:
A. -30 N
Explanation:
not sure but if the box isn't moving then the force opposite of Polly would be equal to the force she's exerting.
Answer:
-30 N....(A)
Explanation:
hope this helps, the person above me is also correct
A 4.5 kg bucket of water is raised from a well by a rope. The acceleration of gravity is 9.81 m/s 2 . If the upward acceleration of the bucket is 4.9 m/s2 , find the force exerted by the rope on the bucket of water. Answer in units of N.
Answer:
The force exerted by the rope on the bucket of water is 66.195 N.
Explanation:
Given;
mass of the bucket, m = 4.5 kg
acceleration of gravity, g = 9.81 m/s²
upward acceleration of the bucket, a = 4.9 m/s²
The upward force applied on the bucket by the rope is calculated as;
F = ma + mg
F = m(a + g)
F = 4.5(4.9 + 9.81)
F = 4.5(14.71)
F = 66.195 N
Therefore, the force exerted by the rope on the bucket of water is 66.195 N.
if your weight is 600 Newton on the earth how far should you go from the centre of the earth so that it will be 300 Newton
Given :
Our weight is 600 Newton on the earth.
To Find :
How far should you go from the center of the earth so that it will be 300 Newton.
Solution :
Acceleration due to gravity at depth d is given by :
[tex]g' = g( 1 - \dfrac{d}{R_e})[/tex]
At earth surface, mg = 600 N ...1)
At depth d, mg' = 300 N ...2)
Dividing 1) and 2), we get :
[tex]\dfrac{g}{g'} = \dfrac{600}{300}\\\\\dfrac{g}{g'} = 2\\\\g = 2g'\\\\g = 2\times g\times ( 1 - \dfrac{d}{R_e} )\\\\1 - \dfrac{d}{R_e} = \dfrac{1}{2} \\\\d = \dfrac{R_e}{2}[/tex]
Therefore, we should go in the depth of distance half the radius of earth.
Two small stereo speakers are driven in step by the same variable-frequency oscillator. Their sound is picked up by a microphone arranged as shown. For what fundamental frequency does their sound at the speakers produce constructive interference? The speed of sound is 340m/sec.
Answer:
The fundamental frequency at which the sound of speakers at the microphone produce constructive interference is 801.076458 Hz
Explanation:
For a given arrangement having constructive interference, we have;
R₁ - R₂ = 2·x = 0 + n·λ
The distance from one speaker to the microphone. R₁ = 4.50 m
The distance between the two speakers = 2.00 m
The angle formed between the direction from the microphone to the speaker closest and the directional path between the speakers = 90°
Therefore, by Pythagoras's theorem, the distance from the speaker furthest from the microphone, to the microphone, 'R₂' is given as follows;
R₂ = √(4.50² + 2.00²) = √(24.25) = 4.9244289009 ≈ 4.924
∴ R₂ ≈ 4.9244289 m
R₂ - R₁ = 4.9244289 m - 4.5 m = 0.4244289 m
For constructive interference, R₂ - R₁ =0.4244289 m = n·λ
For n = 1, we have;
R₂ - R₁ =0.4244289 m = n·λ = 1 × λ = λ
λ = 0.4244589 m
f = v/λ = 340 m/sec/(0.4244289 m) ≈ 801.076458 Hz
Therefore the lowest possible fundamental frequency at which the speakers produce constructive interference, f = 801.076458 Hz
The frequency at which the speakers produce a constructive interference is 801.076 Hz.
Given here,
[tex]R_1[/tex]- The distance from one speaker to the first microphone = 4.5 m
[tex]R_2[/tex] - The distance between microphone and second speaker = ?
The distance between the speakers = 2 m
From Pythagorean theorem,
[tex]R_2= \sqrt {4.50^2 + 2.00^2}\\\\R_2 = \sqrt{24.25} \\\\R_2= 4.924[/tex]
So,
[tex]R_2 - R_1 = 4.9244 \, {\rm m} - 4.5 \, {\rm m} \\\\R_2 - R_1 = 0.4244 \, \rm m[/tex]
For constructive interference,
[tex]R_2 - R_1 = m\lambda[/tex]
Since, m = 1
λ = 0.4244 m
Now, frequency can be calculated by the formula,
[tex]f = \dfrac v\lambda[/tex]
So,
[tex]f = \dfrac {340{\rm \ m/sec}}{(0.4244\; \rm m) }\\\\f = 801.076{\rm \ Hz}[/tex]
Therefore, the frequency at which the speakers produce a constructive interference is 801.076 Hz.
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Please help me.. I will give you 20 points !!
When is a secondary source more helpful than a primary source?
O A. When you want to know the exact data values
B. When you do not need to know the conclusion of the experiment
C. When you want to confirm the conclusion with your own
experiment
D. When you are not an expert in the field being studied in the
experiment
Answer:b but thats what I think
Explanation:
Answer: D. When you are not an expert in the field being studied in the
Explanation: D. When you are not an expert in the field being studied in the
Which Newton’s law is gown below?
First
Second
Third
Pls answer
Answer:
The First law of motion
Explanation:
The firat law states that an object either remains at rest or continues to move at a constant velocety unless acted upon by an external force
Which is an example of a chemical change?
A.) boiling water
B.) melting metal
C.) burning wax
D.) dissolving sugar
Answer:
Burning wax
Explanation:
because in burning, wax reacts with oxygen present in the surrounding and forms carbon dioxide and ash
Which is a possible result of rising ocean temperatures caused by global warming?
formation of dust bowls
increase in strength of hurricanes
rapid evaporation of water in soil
decrease in population due to health threats
Answer:
Increase in strength of hurricanes
Explanation:
A possible result of rising ocean temperatures caused by global warming is increase in strength of hurricanes.
What is global warming?Global warming is an environmental concern characterized by the gradual increase in the Earth's atmospheric temperature.
Global warming can lead to the rise of temperature in air and oceans as well.
One consequence of an increase in ocean temperature is that the strength of hurricanes, which is strong wind accompanied by rain, will be increased.
Therefore, a possible result of rising ocean temperatures caused by global warming is increase in strength of hurricanes.
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What is the acceleration for an object moving with constant speed? Explain your answer
Answer:
What is the acceleration of an object moving at a constant speed?
The Meaning of Constant Acceleration
The data table above show an object changing its velocity by 10 m/s in each consecutive second. This is referred to as a constant acceleration since the velocity is changing by a constant amount each second.
Answer:
there is no acceleration for an object moving with constant speed
Explanation:
it is because acceleration is change in velocity and constant means same or without any change so there is no acceleration for an object which is moving with same speed
hope it helps:)
A student is performing experiments on a particular substance. Which
statement is an observation of a chemical property of the substance?
O A. It burns.
B. It melts.
O C. It floats.
D. Electricity cannot pass through it.
Answer: A.
Explanation:
The number of forces that act on a book after being pulled by an string and start moving on a table is
1.
2.
3.
4
how many muscles make up the human body
Answer:
650......................
why will light from the sun change the color of the cloth when the light from the desk lamp does not
Answer:
Because the sun gives off a type of light that carries energy, and light from the desk lamp does not.
Explanation:
All of the energy from the Sun that reaches the Earth arrives as solar radiation, part of a large collection of energy called the electromagnetic radiation spectrum. Solar radiation includes visible light, ultraviolet light, infrared, radio waves, X-rays, and gamma rays. Radiation is one way to transfer heat.
During which change of states do atoms lose energy?
Answer: freezing
Explanation:
1. Miranda wraps her hands around a mug of hot tea. The heat from the hot tea is being transferred to the mug, and then to Miranda’s hands, mostly by *
convection
reflection
radiation
conduction
Two balls, a foam ball and a golf ball, are placed into a pail of water. The golf ball sinks. Why does a foam ball float and a golf ball sink when both are placed into water?
Answer:
The golf ball has a greater mass than the foam ball
Explanation:
If a problem has more than one system of interest, more than one free-body diagram is required to describe the external forces acting on the different systems.
1.True
2.False
Mechanical energy is the
_______ of kinetic energy and potential energy.
Answer:
machine
Explanation:
What would be the average speed of a runner who finished a 400 meter race in 50 seconds?
Answer:800
Explanation:about
What is the weight of a 36 kg toy car?
Answer:
About 79 lbs (pounds)
Explanation:
Which idea did Ptolemy’s model use to explain why the planets appeared to move backward as they moved in their orbits?
The planets spun in epicycles.
The planets rotated on their axes.
The planets revolved around the Sun.
The planets were made of different materials.
Answer:
The planets spun in epicycles.
Explanation:
Ptolemy's model used to explain that the planets spun in epicycles.
What is Ptolemy's model? How it was explained?
Ptolemy placed the Earth at the center of the geocentric model. The system of planetary motions according to which the earth is at the center with the sun, moon, and planets revolving around it and each orbit except for the sun and moon is composed of a principal circle upon which moves a smaller circle carrying the planet. As he knows about the planetary motions and ideas about the universe was a set of spheres that surrounds the earth. He also believed that the moon has the orbit which is closest to the earth, the Mercury , the Venus and the sun.
According to Ptolemy he considered and mentioned completely about 48 constellations.
Hence, Option A is the correct answer.
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Which Olympic events the most muscular stretch
Answer:
It is gymnastics.
identify the type of wave in the picture please asap
Answer:
It is transverse wave
Explanation:
Explanation:
yes, it's a transverse wave
hope it helps you
PLEASE ANSWER IN COMPLETE SENTENCE!!!
What is the relationship between Earth’s mass and its atmosphere?
Answer:
Mass is proportional to gravity and gravity is necessary to hold an atmosphere, therefore mass would seem to be very important for the ability for a body to have an atmosphere. However there are quite a few examples that show that it doesn't require that much mass to get an atmosphere.
Explanation:
Answer + Explanation : Mass is proportional to gravity and gravity is necessary to hold an atmosphere, therefore mass would seem to be very important for the ability for a body to have an atmosphere.
1 Pascal is equal to N/cm
True
False
Answer:
False
Explanation:
Pascal is a pressure of one newton per square metre, or, in SI base units, one kilogram per metre per second squared.
Pa = N/m^2
You make a(n) _____ by fastening together usually perpendicular parts with the ends cut at an angle.
Answer:
Miter joint
Explanation:
Made by fastening together usually perpendicular parts with the ends cut at an angle
This table lists traits of four types of vertebrates. Each trait first appeared in a common ancestor of the animals that evolved later. These traits are used to build a branching diagram
Based on the information in the table, which animal belongs in the spot labeled “C” on the branching diagram?
Pls help
Frog belong to the spot 'c'
The organisms with the fewest number of shared characteristics are at the bottom. The organisms with the greatest number of shared characteristics are found at the top.What is branching diagram?a branching diagram show the evolutionary relationships among various biological species based upon similarities and differences in their morphological or genetical characteristics.
Hence the frog is correct answer.
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plz i need help please help
Answer:
if you look it up i think u can find it it could be a mealltiod Co 27
Explanation:
help me please???!!!!
Stars emit different wavelengths of visible light due to their different
temperatures. How does this phenomenon support the particle model of
light?
A. It is the result of interference.
B. It is the result of diffraction.
C. It is the result of the photoelectric effect.
D. It is the result of blackbody radiation.
Answer:
D
Explanation:
Just did it
The particles model of light supports the the photoelectric effect, where, light in the form of tiny packets called photons when hit on a metal surface it ejects electrons.
What is photelectric effect?Photoelectric effect is discovered by Albert Einstein. When a light ray hit on a solid surface, the photon or light particle emits from the surface which is having the equal energy as that of the incident photon.
According to wave -particle duality of matter, light can exhibit both particle and wave nature. If light behaves as a particle of specific energy, the light particle is called photon.
Stars emit light in different wavelengths of visible light at different temperatures. The wavelength is equal to the speed of light divided by the frequency. The excitation of electron depends on the temperature also. This effect indicating the particle nature of light.
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Which measurement can she expect once the water begins to boil??
Answer:
200
Explanation:
has to be long this us just random words anseer is b. 100