Answer:
Reflective surface
Explanation:
Ice is a reflective surface because most the of the light waves that hits on it bounces off.
When a surface is smooth and polish, it acts a reflector. When a surface is jagged and not smooth light does not readily reflect. Reflection is through the incident angle of the light waves.Therefore, snow is a reflective surface.
An underwater sound source emits waves of frequency 30 kHz in all directions. How does the intensity of the waves (in Watts/m2) vary with distance r from the source?
a) 1/r^3
b) 1/r^2
c) 1/r
d) None of above
When an underwater sound source emits waves of frequency 30 kHz in all directions, the intensity of the waves (in Watts/m2) vary with distance r from the source by the relation 1/r²
As the intensity mechanical sound wave is inversely proportional to the square of the distance from the source, therefore the correct option is B.
What is the Wavelength?Wavelength can be understood in terms of the distance between any two similar successive points across any wave for example wavelength can be calculated by measuring the distance between any two successive crests.
It is the total length of the wave for which it completes one cycle.
The intensity of a mechanical wave is inversely proportional to the square of the distance from the source.
An underwater sound source emits waves of frequency of 30 kHz in all directions, the intensity of the waves (in Watts/m2) varies with distance r from the source by the relation 1/r², therefore the correct option is B.
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all the elements are found on earth, where were they formed?
1. in the sun
2. in ancient stars
3. in earths core
4. in the gas cloud that formed earth
Answer:
in the Earths core
Explanation:
A car start from rest accelerate uniformly at rate of 2 m/sec2. Its velocity after 5 seconds will be:
Answer:
nononononononononononononnn
Explanation:
Answer:
Read below to understand
Explanation:
acceleration = change in velocity / change in time
(a = v/t)
You have acceleration and time given so you need to rearrange the equation to solve for velocity
V = a * t
V = 2 * 5
Velocity is 10 m/s
A cylinder of mass 250 kg and radius 2.60 m is rotating at 4.00 rad/s on a frictionless.
Two more identical nonrotating cylinders fall on top of the first. Because of friction
between the cylinders they will eventually all come to rotate at the same rate. What is this final angular velocity?
Answer:
The angular momentum of a cylinder, when it is rotating with constant angular velocity is Lini =Iωi
. When two cylinders are added to the rotating cylinder, which are identical in their dimensions, the moment of inertia of the entire system increases (since mass increases). The final moment of inertia will be 3I
Since friction exist, all the cylinders start rotating with same angular velocity, the new angular velocity can be calculated using conservation of angular momentum
Thus, Iωi =3Iωf ⟹ωf =ωi/3 = 0.33ωi
A car accelerates from rest to a certain velocity in a certain time. Assume that there is no friction, and that the engine power is constant. Consider the following scenarios independently. How long would it take to reach double the velocity (also from rest)
Answer:
it will take half of the initial time to reach double the velocity
Explanation:
Given that a car accelerates from rest to a certain velocity in a certain time.
Since the car accelerate from rest, the initial velocity U = 0
Using the first equation of motion,
V = U + at
V = at
Assume that there is no friction, and that the engine power is constant. Consider the following scenarios independently. How long would it take to reach double the velocity (also from rest)
That is V = 2V
Using the same formula ,
2( at ) = at
2T = t
T = t/2
Therefore, it will take half of the initial time to reach double the velocity
My question is on the picture
Answer:
Measure change in temperature after long call
Explanation:
Glucose is a carbohydrate.
True
0r False
Answer: True
Explanation: Glucose is a carbohydrate.
It takes 25.7 N to push a crate
at a constant speed across flat
ground where uk
= 0.238.
What is the normal force acting
on the crate?
(Unit = N)
Answer:
108 N
Explanation:
Divide the force by uk to get the normal force
(25.7)/(0.238) = 107.98 N = 108 N
Answer:
107
Explanation:
A ball is thrown upward in the air with an initial velocity of 40 m/s. How long does it take to
reach back to the point it was thrown from?
Answer:
You need the definition of acceleration (a=Vf-Vi/t) and 1 equation of linear motion (deltaX = Vi×t + 1/2×a×t^2). Since you know a is constant (gravity) and you know your initial Vi to be 40 m/s and your final velocity Vf to be zero (maximum height), then you can use thhe definition of acceleration to find time.
-9.81m/s^2 = (0-40m/s)/t
t = (-40)/(-9.81) s
t = 4.077s
Now that you have time, you should know all but deltaX in the equation of linear motion.
dX = (40m/s)(4.077s) + (1/2)(-9.81m/s^2)(4.077s)^2
dX = (163.099m) — (81.549m)
dX = 81.55m
Are these bones axial, appendicular
or both?
Answer:
Axial and Appendicular Skeletons The axial skeleton forms the central axis of the body and consists of the skull, vertebral column, and thoracic cage. The appendicular skeleton consists of the pectoral and pelvic girdles, the limb bones, and the bones of the hands and feet. Figure 6.41.
Explanation:
A rubber cord catapult has cross-sectional area
25mmand initial length of rubber cord is 10c.
Its is stretched to 5cm and then released to
project a missile of mass 5gm. Taking
Yubber = 5x108N/m² velocity of projected
missile is :
(1) 20ms -
(2) 100ms
(3) 250ms
(4) 200ms)
a car get slips in a mud
Answer:
So, if the car slips in mud it will either skid or slide depending on the size of the mud puddle.
Does this work?
2.9030 has 4 significant digits.
TRUE OR FALSE
A person has a mass of 1000 g and an acceleration of 20 M/S/S what is the force on the person
Answer:
The answer is 20 NExplanation:
The force acting on an object can be found by using the formula
force = mass × accelerationFrom the question
mass = 1000 g = 1 kg
acceleration = 20 m/s²
We have
force = 20 × 1
We have the final answer as
20 NHope this helps you
A force vector has a magnitude of 42 N and is applied at an angle of 108°
above the eastern horizontal.. Determine they component of this force
vector
0 -15 N
O -13 N
39.9 N
35 N
Explain which planets have seasons and why some planets have none at all.
Discuss which planet has seasons most similar to earth and why.
Discuss additional factors that some planets have that affect their seasons.
What fact about other planet’s seasons most surprised you and what did you find the most interesting? Why?
Answer:
Some planets have seasons some don't bc of the distance from the sun some of them are too cold or too hot to have seasons
PLEASE PLEASE HELP PICTURE INCLUDED
Answer:
an electro magnet is technology contain at least one permanent magnet
A shot-putter exerts an unbalanced force of 128 N on a shot giving it an acceleration of 19
m/s2. What is the mass of the shot?
Answer:
128 is the ans cuz N is also lnown as mass
Explanation:
128
Which atmospheric layer gets warmer as altitude increases and contains the ozone layer?
Answer:
stratosphere
Explanation:
In the stratosphere, temperature increases with altitude. The stratosphere contains the ozone layer, which protects the planet from the Sun's harmful UV radiation.
Stratosphere is the atmospheric layer which gets warmer as the altitude increases and contains the ozone layer.
What is Stratosphere?The stratosphere is a layer of the Earth's atmosphere. It is the second layer of the atmosphere as we go upward into the atmosphere height. The troposphere is the lowest layer of the globe, which is present right below the stratosphere. The next higher layer of the atmosphere above the stratosphere is the mesosphere.
In the stratosphere layer, the temperature increases with the increase in the altitude range. The stratosphere layer contains the ozone layer, which works in the protection of the planet from the Sun's harmful ultraviolet radiations which could lead to cancer.
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In the periodic table, the number of valence electrons in each element decreases from left to right across each period.
Select one:
O True
O False
A box is pushed using 500 joules of energy. The amount of energy produced is
50 J. Calculate the efficiency.
As part of their research on cell reproduction, Ms. Kelly's biology class designed various experiments to determine the best conditions for budding, or asexual reproduction, in common yeast cells. The students added sucrose as a source of food for the yeast and each group added water of a different temperature to the yeast-sugar mix. They used a light microscope to observe and count the yeast cells.
Based on the recorded data, what observation did the students make regarding the growth of yeast cells?
A) Once the temperature reached 50oC, the yeast died.
B) The size of individual yeast cells increased with an increase in temperature.
C) Increased temperature played no role in increasing the number of yeast cells.
D) The number of yeast cells increased as the temperature of the water increased.
A car is pushed and travels 12 m. The same car is then pushed and it travels 15m. What
could have happened? Select 2 answers.
The mass was decreased
The force was increased
The force was decreased
The mass was increased
=========================================
Explanation:
If the force is kept the same, but the mass was decreased, then the car will travel further. The less mass an object has, the less inertia it has. Inertia is the tendency for the object to stay at rest if it's initially at rest (or the tendency for the object to stay in motion if already in motion).
If the mass is kept the same, but the force was increased, then the object will travel further than before. The same idea applies as discussed in the last paragraph.
------
If the force was decreased and mass kept the same, then there is less push, which results in the object traveling a shorter distance. If the mass is increased but the force kept the same, then the object moves a shorter distance because there's more inertia to overcome. There are more particles needed to be moved and they resist motion if at rest.
Using complete sentences and correct punctuation and grammar answer the following question. Must be at least 3 sentences.
Explain why Eclipses do not occur every month.
Answer: A solar eclipse occurs when the moon passes in between the Earth and sun, casting a shadow down on the surface of our planet. If you're in the path of the shadow, the moon destroys the sun. No, wait, I mean the moon blocks the sun briefly.A lunar eclipse happens when the moon passes through the Earth's shadow. We see one limb of the moon darken until the entire thing is in shadow.An eclipse does not occur every month, because one month after an eclipse the relative geometry of the Sun, Moon, and Earth has changed. As seen from the Earth, the time it takes for the Moon to return to a node, the draconic month, is less than the time it takes for the Moon to return to the same ecliptic longitude as the Sun.
Explanation:
Answer:
Because the moon's orbit wobbles up and down with respect to the Earth, the satellite's shadow can be too high or too low to cause a solar eclipse. If the moon partially covers the sun for a given location, that area experiences a partial solar eclipse. But if the moon fully covers the sun, it will cause either a total solar eclipse or an annular solar eclipse; that's when a bright ring of light is still visible in the sky around the dark silhouette of the moon.
Newton’s third law says that every time there is an interaction force, there is also a force that is ______________________ in size and acts in the ____________________________ direction .
Answer:
equal, opposite
Explanation:
Newton’s third law says that every time there is an interaction force, there is also a force that is equal in size and acts in the opposite direction .
The jogger ran 3km east.
4. Look at the bottom figure. Suppose that a car is 20 km due north of New York City. The car
travels north toward Albany until it is 100 km due north of New York City.
Answer: d
Explanation:
A rock climber is going up a narrow space between two vertical rocks. The distance between the rocks allows the climber to brace herself using friction, where her feet are flat and in contact with one rock to the left, and her legs are straight horizontal and her back is flat against a rock on the right. The coefficient of static friction between her shoes and the rock on the left is 1.2, and between the rock at right and her back is 0.8. The climber relaxes until she is on the verge of slipping on both sides.
(a) Draw a FBD for the climber
(b) What fraction of her weight is supported by the frictional force on her shoes?
Answer: b
Explanation:
According to the kinetic theory, what happens when the temperature of water
increases?
The water molecules increase their speed.
The water molecules do not change speed.
The water molecules decrease their speed
PLEASE HELP
water vapor is what kind of gas?
Answer:
the gaseous phase of water
Explanation:
"It is one state of water within the hydrosphere. Water vapor can be produced from the evaporation or boiling of liquid water or from the sublimation of ice. "
hope this helps!!
Water vapor is a greenhouse gas.
I know this is a simple answer, but I sincerely hope this helped!
can you pls give a question about science. like why does the sky blue? PLS HELPPP ASAP