The pencil is clearly an opaque object because we cannot see through it and therefore forms a shadow.
Which of the following is a good way to look for jobs today?
1.Networking on LinkedIn
2.Checking the bulletin board at the local grocery store
3.Putting a résumé on a job hunting website
4.Searching the help wanted section in the newspaper
I think it's
1. Networking on LinkedIn
A form of oxygen with three atoms of
oxygen bonded together instead of two is
called what?
A. triple oxygen
B. ozone
C. oxygen-3
D. trioxygen
Answer:
ozone, letter b
ozone is basically an allotrope of oxygen having three atoms instead of two.
What is being despited in this picture
Answer:
i am guessing for reflection but not so sure
Traveling waves propagate with a fixed speed usually denoted as v (but sometimes c). The waves are called __________ if their waveform repeats every time interval T. Traveling waves propagate with a fixed speed usually denoted as (but sometimes ). The waves are called __________ if their waveform repeats every time interval . transverse longitudinal periodic sinusoidal
Answer:
Periodic.
Explanation:
Electromagnetic waves is a propagating medium used in all communications device to transmit data (messages) from the device of the sender to the device of the receiver.
Generally, the most commonly used electromagnetic wave technology in telecommunications is radio waves.
Radio waves can be defined as an electromagnetic wave that has its frequency ranging from 30 GHz to 300 GHz and its wavelength between 1mm and 3000m. Therefore, radio waves are a series of repetitive valleys and peaks that are typically characterized of having the longest wavelength in the electromagnetic spectrum.
Basically, as a result of radio waves having long wavelengths, they are mainly used in long-distance communications such as the carriage and transmission of data.
Generally, a fixed speed is used for the propagation of traveling waves and this speed is usually denoted with the variable "v" or sometimes "c."
Furthermore, if the waveform of a traveling wave is repeated every time at specific intervals T, it is referred to as periodic wave.
Mathematically, the period of a traveling wave is given by the formula;
[tex] Period = \frac {1}{T} [/tex]
Where;
T is the time measured in seconds.
Kinetic energy is the energy of motion and increases with the speed of the wave.
a. True
b. False
Potential energy is the energy of gravitational pull on the wave.
a. True
b. False
Which one of the statements below is true about mechanical waves?
They must travel in empty space.
They can travel in a vacuum.
Both sound and light are examples of mechanical waves.
They require a medium to travel through.
Answer:
Both sound and waves
Explanation:
Thank me later
if one stand of DNA reads as AATTCCGGATCG, what would the opposite strand bases be?
What are the 3 least important cell parts and why
Answer:
The three main/basic parts of the cell are:
Cell Membrane (Plasma Membrane)
Cytoplasm
Nucleus
Explanation:
Each cell is surrounded by a lipid-rich Cell membrane (also called the Plasma Membrane) that forms a boundary between the cell and its environment.The membrane encloses the Cytoplasm, which includes all cell contents (except the Nucleus, in cells that have one). Cytosol is the fluid of Cytoplasm.Nucleus is the central part of an atom, and the process of milk production and secretion begins here; the organelle that contains DNA in eukaryotic cells.Which of the following best describes
pollutants?
A. harmful substances in the air, water, or soil
B. radioactive particles that pass through the atmosphere
C. oxygen molecules that are released by plants
D. beneficial substances that increase overall health
Answer:
A. harmful substances in the air, water, or soil
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A vector is
In English
NO LINKS PLEASE
At what speed do a bicycle and its rider, with a combined mass of 90 kg
k
g
, have the same momentum as a 1500 kg
k
g
car traveling at 4.0 m/s
m
/
s
?
Answer:
2
Explanation:
Which of the following is an example of an electromagnetic wave?
a radio wave
a water wave
the oscillation of a spring
sound waves
In many places on Earth, humans are responsible for the removal of grasses, shrubs, trees, and other plants with roots that hold soil in place. This activity is best described by which of the following? *
A) deforestation
B) urbanization
C) air pollution
D) rise in sea level
Refracts light to form an image on the lining of your eyeball?
Answer:
In a healthy eye, the cornea bends or refracts light rays so they focus precisely on the retina in the back of the eye. The back of the eye is lined with a thin layer of tissue containing millions of photoreceptor (light-sensitive) cells. This is the retina, where light rays focus into an upside-down image.
Explanation:
You serve a basketball with a mass of 5 kg. If the ball leaves your hand at 30 m/s what is
the kinetic energy?
A) 150 joules
B) 2,250 joules
C) 75 joules
Which one of the statements below is true about mechanical waves?
They must travel in empty space.
They can travel in a vacuum.
Both sound and light are examples of mechanical waves.
They require a medium to travel through.
Answer:
They require a medium to travel through.
Explanation:
Earthquakes produce two kinds of seismic
waves: he longitudinal primary waves (called
P waves) and the transverse secondary waves
(called S waves). Both S waves and P waves
travel through Earth's crust and mantle, but
at different speeds; the P waves are always
faster than the S waves, but their exact speeds
depend on depth and location. For the pur-
pose of this exercise, we assume the P wave's
speed to be 8560 m/s while the S waves travel
at a slower speed of 5760 m/s.
If a seismic station detects a Pwave and
then 30.5 s later detects an S wave, how far
away is the earthquake center?
Answer in units of km.
Mi
Answer:
d
=
s
t
Explanation:
distance = speed * time
here, the distance is from the earthquake centre to the seismic station.
both the P and S waves travel from the earthquake centre before being detected by the seismic station, so the distance is the same for both.
the speeds are given as
8740
m
/
s
for the P wave and
4100
m
/
s
for the S wave.
we also know that the P wave arrives
47.4
seconds before the S wave.
we do not know the time that the P wave takes to travel, but we can denote it as
t
P
.
the time that the S wave takes to travel can be denoted as
t
P
+
47.4
, where time is in seconds.
for the S wave, speed * time is
4100
⋅
(
t
P
+
47.4
)
for the P wave, speed * time is
8740
⋅
t
P
.
since the distances that they travel are the same, the two expressions for speed * time are equal.
4100
⋅
(
t
P
+
47.4
)
=
8740
⋅
t
P
if you expand the brackets, you can find that
4100
t
P
+
194340
=
8740
t
P
then you can subtract
4100
t
P
:
4640
t
P
=
194340
and divide by
4640
to find
t
P
, which is the time that P takes to travel:
t
P
=
41.883
...
seconds
since distance = speed * time, the distance that the P wave travels is
t
P
⋅
the speed of P.
this is
41.883
s
⋅
8740
m
/
s
, which gives
366057.42
m
.
in kilometres, this is
366
k
m
to
3
significant figures.
In rectilinear motion, motion depends on a?
Answer:
The object moving in a straight path is called linear or rectilinear motion.
An object is said to be in rectilinear motion if it changes its position,along a straight line path.
Explanation:
example: A car moving in a straight road.
A jet moving straight in air
MY NOTES A spring with a mass of 2 kg has a damping constant 14 kg/s. A force of 3.6 N is required to keep the spring stretched 0.3 m beyond its natural length. The spring is stretched 0.6 m beyond its natural length and then released. Find the position of the mass at any time t. (Assume that movement to the right is the positive x-direction and the spring is attached to a wall at the left end.)
Electrons and protons travel from the Sun to the Earth at a typical velocity of 3.83 ✕ 105 m/s in the positive x-direction. Thousands of miles from Earth, they interact with Earth's magnetic field of magnitude 3.04 ✕ 10−8 T in the positive z-direction. Find the magnitude and direction of the magnetic force on a proton. Find the magnitude and direction of the magnetic force on an electron.
Answer:
[tex]F=2.84*10^{-26}N[/tex] & -y direction
[tex]F=2.84*10^{-26}N[/tex] & +y direction
Explanation:
From the question we are told that:
Speed of electron [tex]V_e=3.83 * 10^5 m/s[/tex] +x direction
Earths magnetic field [tex]B_e=3.04 * 10^-^8[/tex] +z direction
a)
Generally the equation for magnetic force [tex]F_m[/tex] is mathematically given by
[tex]F=q(V_e*B_e)[/tex]
where
[tex]q=1.6*10^{-19}c\\\=i*\=z=-\=j[/tex]
[tex]F=1.6*10^{-19}(3.83 * 10^5 m/s*3.04 * 10^-^8)[/tex]
[tex]F=1.6*10^{-19}(3.83 * 10^5 m/s*3.04 * 10^-^8)[/tex]
[tex]F=-2.84*10^{-26}N \=j[/tex]
Magnitude & Direction
[tex]F=2.84*10^{-26}N[/tex] -y direction
b)
Generally the equation for magnitude and direction of the magnetic force on an electron. is mathematically given by
[tex]\=F'=-1.6*10^{-19}(3.83 * 10^5 m/s*3.04 * 10^-^8)[/tex]
[tex]\=F'=-2.84*10^{-26}N \=j[/tex]
Magnitude & Direction
[tex]F=2.84*10^{-26}N[/tex] & +y direction
E
Please select the word from the list that best fits the definition
freezing point of carbon dioxide
A. Meter
B. Liter
C. Kilogram
D. Kelvin
A ball with a weight of 70 N hangs from a string that is coiled around a 3 kg pulley with a radius of 0.4 m. Both the ball and the pulley are initially at rest. The rotational inertia of the pulley is 0.5mr2 and the ball is released from rest. Calculate the ball's velocity after it falls a distance of 2 meters.
Answer:
v = 6.195 m / s
Explanation:
For this exercise we can use the conservation of energy, for the system formed by the ball and the pulley
starting point. Higher before releasing the system
Em₀ = U = M g h
final point. When the ball has lowered h = 2
Em_f = K = ½ M v² + ½ I w²
the energy is preserved
Em₀ = Em_f
M g h = ½ M v² + ½ I w²
angular and linear velocity are related
v = w r
w = v / r
indicate that the moment of inertia is
I = ½ m r²
we substitute
M g h = ½ M v² + ½ (½ m r²) (v/r) ²
½ v² (M + [tex]\frac{1}{2}[/tex] m) = M g h
v² = [tex]2gh \ \frac{M}{M + \frac{m}{2} }[/tex]
let's calculate
v = [tex]\sqrt{ 2 \ 9.8 \ 2 \ \frac{70}{70 + 1.5} }[/tex]
v = 6.195 m / s
Do Planets with more mass have more gravity than planets with less mass
A horizontal force of 300.0 N is used to push a 145-kg mass 30.0 m horizontally in 3.00 s. Calculate the power developed.
Answer:
3 * 10³J/s
Explanation:
Given :
Force applied, F = 300 N
Distance, d = 30 m
Time, t = 3 seconds
Power, P = Workdone / time
Recall :
Workdone = Force * distance
Workdone = 300 N * 30 m = 9000 Nm
Workdone = 9 * 10³ J
Power = (9 * 10³ J) / 3s
Power = 3 * 10³J/s
help its due in 13 minutes!!!!
Answer:
sedimentary rock formed over a long period of time. small pieces of rock called sediments are carried away and deposited in layers. over time more and more layers of sediments form, pressing down on the layers below. the weight of the layers squeezes the sediments together during the process know as compaction. as the water is squeezed out, crystals form. the sediments stick together. this process is called cementation
What is the angle of refraction for a beam of light moving from a prism to air if the angle of incidence is 30° and the prism’s index of refraction is 1.6?
Answer:
Refraction involves passing through a boundary (choice a) and changing speed (choice ... A ray of light in air is incident on an air-to-glass boundary at an angle of 30. ... If the index of refraction of the glass is 1.65, what is the angle of the refracted ray ... The critical angle is the angle of incidence (which is always in the more ...
Explanation:
Please solve it.... Urgent
Answer:
a) ferromagnetic type, b) superconductor or ferromagnetic
Explanation:
In substances, magnetism is the result of the magnetic moments of the electrons in their orbits and of the spin.
These two let us take interacting magnetic between them, if the sum of these magnetic moments is maximum we have a material of the ferromagnetic type, which is represented in figure a, where all the magnetic moments are aligned in one direction and this type of material is a magnet permanent.
Figure b shows a material where the magnetic moments have a circular shape, so the total moment is zero.The type of substrate material can have several possibilities
* The most test is that the substrate material is a superconductor where the marked areas are the superconducting magnetic areas and the areas without spine are the normal areas
* Another possibility is that the material is ferromagnetic, that is, there are several magnetic sub-networks in different orientation, resulting in a random field, the material is not a permanent magnet
Two identical speakers are set some distance apart in a large open field. Both are producing sound, in unison, with a wavelength of 4 m. An observer wandering around the field notices that the sound is surprisingly loud at certain locations and unusually quiet at others. The observer concludes that this is the effect of interference between the two sources of sound waves. For each location, indicate which sort of interference would occur at that point.
Answer:
Constructive interference occurs at the surprisingly loud locations and destructive interference occurs at the unusually quiet locations.
Explanation:
This is because, constructive interference tends to combine the effects of the wave when they are in phase (that is, moving in the same direction), which thus amplifies the effect and produces surprisingly loud sounds at those locations, while destructive interference occurs when the waves are out of phase with each other(that is, move in opposite directions) and thus, their effects tend to cancel out thus producing locations of unusually quiet sounds.
A 2 kg brick is moving at a speed of 3 m/s. What is the kinetic energy of the brick?
Explanation:
it's generally proven that the formula for kinetic energy is k. e = ½mv²
= ½×2×3
=3
As air pressure decreases, what happens
to the density of the atmosphere?
A. increases
B. decreases
C. stays the same
D. not enough information to tell
Answer:
Increases
Explanation:
This is because if there are more gas particles available within a given area, the greater the air density. Therefore, the greater the air density, there will be more gas particles per unit volume. Which indicate that there are more air particles bombarding with a surface. Therefore, the air pressure increases as the air density increases and visa versa.