Answer:
The speed of sound in air is lower compared to in solids and liquids.
Explanation:
Sound is a wave that can be generated by a vibrating body. Its speed through different media differs due to the nature of the media.
Since the molecules of solids are closely packed, sound can be easily transferred from one molecule to another at a faster rate. Thus, the high speed of sound in solids.
In liquids, the molecules are not as closely packed as solids. So that the speed of sound though liquids is lower compared to that of solids. Gases has its molecules farther apart, thus making the speed of sound through it the lowest compared to solids and liquids.
Therefore the sound of the batter hitting the ball is heard latter, due to its lower speed through the air.
A diode, which allows current to flow in one direction only, consists of two types of semiconductors joined together.
True or false
Answer:
True.
Explanation:
A diode, which allows current to flow in one direction only, consists of two types of semiconductors joined together.
A semiconductor can be defined as a crystalline solid substance that has its conductivity lying between that of a metal and an insulator, due to the effects of temperature or an addition of an impurity. Semiconductors are classified into two main categories;
1. Extrinsic semiconductor.
2. Intrinsic semiconductor.
An intrinsic semiconductor is a crystalline solid substance that is in its purest form and having no impurities added to it. Examples of intrinsic semiconductor are Germanium and Silicon.
In an intrinsic semiconductor, the number of free electrons is equal to the number of holes. Also, in an intrinsic semiconductor the number of holes and free electrons is directly proportional to the temperature; as the temperature increases, the number of holes and free electrons increases and vice-versa.
In an intrinsic semiconductor, each free electrons (valence electrons) produces a covalent bond.
Help me plsssss I need. The question is confusing and so sorry if it blurry
Answer:
400Pa
Explanation:
The question asks for you to substitiute in known values into the formula to solve for pressure which is calculated through force/area
in this instance
force=300N
area=0.75m^2
substitute in the values and solve for pressure
300/0.75=pressure
pressure=400Pa (the si unit for pressure is Pa or pascal)
Explain why the protons can never change for a particular element. What subatomic particles can change and what do they form?
Protons can never change for any particular element because they're in the nucleus and the force keeping them there is extremely strong and hard to overcome. Electrons, however, orbit the nucleus and they change all the time. When electrons either leave or join an atom they form ions.
Positive ions (cations) are when electrons leave, so the positive charge is greater than the negative charges, and negative ions (anions) are when electrons join so the negative charge is greater than the positive charge.
hope this helps!
1.Galileo conducted experiments from the top of the Leaning Tower of Pisa. If he dropped a piece of burlap tied into a ball with twine and a 2-pound rock at the same time, what would he have seen and why? (5 points)
Answer:
The time for both of the balls to reach the ground would be the same.
Explanation:
If no air resistance is present, the rate of descent depends only on how far the object has fallen, no matter how heavy the object is. This means that two objects will reach the ground at the same time if they are dropped simultaneously from the same height. ... In air, a feather and a ball do not fall at the same rate.
9. During an egg toss, a catcher must cushion the egg by maximizing the time it takes to stop the
egg. Find the impulse applied to a 60.0-gram egg, if the egg has an initial velocity of 6.0 m/s as it
first touches the catcher's hand, and the egg is stopped within 50.0 cm.
Answer:
the impulse experienced by the egg is 0.053 kgm/s.
Explanation:
Given;
mass of the egg, m = 60 g = 0.06 kg
initial velocity of the egg, u = 6 m/s
height moved by the egg, h = 50 cm = 0.5 m
Determine the final velocity of the egg as it moves upward;
v² = u² + 2(-g)h
v² = u² - 2gh
where;
v is the final velocity
-g is negative acceleration due gravity as it moves upward
v² = 6² - 2(9.8 x 0.5)
v² = 26.2
v = √26.2
v = 5.12 m/s
The impulse applied to the egg is the change in linear momentum;
J = ΔP
ΔP = mu - mv
ΔP = m(u - v)
ΔP = 0.06(6 - 5.12)
ΔP = 0.053 kgm/s
Therefore, the impulse experienced by the egg is 0.053 kgm/s.
An archer defending a castle is on an 15.5 m high wall. He shoots an arrow straight down at 22.8 m/s. How much time does it take to reach the ground? (Unit = s) Watch your minus signs!
Answer:
about 602 milliseconds
Explanation:
The motion can be approximated by the equation ...
y = -4.9t^2 -22.8t +15.5
where t is the time since the arrow was released, and y is the distance above the ground.
When y=0, the arrow has hit the ground.
Using the quadratic formula, we find ...
t = (-(-22.8) ± √((-22.8)^2 -4(-4.9)(15.5)))/(2(-4.9))
= (22.8 ± √823.64)/(-9.8)
The positive solution is ...
t ≈ 0.60195193
It takes about 602 milliseconds for the arrow to reach the ground.
In 1929, American astronomer Edwin Hubble discovered that distant galaxies were moving away from us. He found that light from distant objects in the universe shifted in frequency towards the red color on the electromagnetic spectrum, which tells us that the objects are receding away from us.
What phenomenon is described in the passage above? Select the best answer from the choices below.
a
The Doppler Shift
b
Hubble's Law
c
The Big Bang
d
Dark matter
Answer:
it is the Hubble law
Explanation:
Hubble's law, also known as the Hubble–Lemaître law, is the observation in physical cosmology that galaxies are moving away from the Earth at speeds proportional to their distance. In other words, the farther they are the faster they are moving away from Earth.
Answer:
The hubble law
is the observation in physical cosmology that galaxies are moving away from the Earth at speeds proportional to their distance. In other words, the farther they are the faster they are moving away from Earth.
Whats the word for when "velocity equals 0 and direction changes" Its 14 letters, and I have _ _ _ _ i _ _ _ _ _ h_ i _ _ t
Answer:
Maximum Height
Explanation:
The maximum height is the highest point reached by a projected body. At this point, final velocity, v of the body is equal to 0; because upward motion is at its peak and the body start to fall again.
Hence, final velocity v is always 0 at this maximum point and the direction of motion changes from upward to downward.
Final velocity at this maximum height is zero because of the directional change experied by the object and the fact that upward motion of the body terminates at this point.
PLEASE HELP ME I NEED THE ANSWER FAST 1 A diver diving into a pool has
a. no energy b. potential energy c. kinetic energy
Answer:
C
Explanation:
A diver diving into a pool has kinetic energy when they hit the water, and that energy transfers and is given to the water, which splashes.
A steel ball bearing is released from a height H and
rebounds after hitting a steel plate to a height H.
What is true about the collision with the steel plate?
Answer:
ELASTIC collision
kinetic energy is conservate
Explanation:
As the ball bounces to the same height, it can be stated that the impact with the floor is ELASTIC.
As the floor does not move the conservation of the moment
po = pf
-mv1 = m v2
- v1 = v2
So the speed with which it descends is equal to the speed with which it rises
Therefore the kinetic energy of the ball before and after the collision is the same
Answer:
CORRECT (SELECTED)
It is elastic since kinetic energy was conserved.
Explanation:
G8_SCIENCE_BSA_20_21
DOBSON, DAMIER
1 of 751 of 75 Items
Assessment started: G8_SCIENCE_BSA_20_21.
Item 1
Grade 8 Science
Session #1: Questions 1-38
1. The Herztsprung-Russell diagram shown below is used to group stars based on specific physical properties unique to each star.
Based on the diagram, which of the following describes the physical characteristics of Barnard’s Star?
hot and dim
hot and dim
cool and dim
cool and dim
hot and bright
hot and bright
cool and bright
cool and bright
Item 1
Grade 8 Science
Session #1: Questions 1-38
1. The Herztsprung-Russell diagram shown below is used to group stars based on specific physical properties unique to each star.
Based on the diagram, which of the following describes the physical characteristics of Barnard’s Star?
hot and dim
hot and dim
cool and dim
cool and dim
hot and bright
hot and bright
cool and bright
cool and bright
Answer:
Do it yourself
Explanation:
gsh
Answer: cool and dim :)
Explanation:
A fault is formed by the movement of a ___ plate boundary
A.convergent
B.traditional
C.divergent
D.transform
When a substance easily dissolves in a liquid, it has high solubility in that liquid. When a substance does not easily dissolve in a liquid, it has low solubility in that liquid. Solubility of a gas in water describes how well the liquid can "hang on" to gas, instead of releasing it into the air. Based on the results of your experiment, do you think that CO2 has a higher solubility in hot water or cold water? Why?
Answer:
CO2 has a higher solubility in cold water
Explanation:
The solubility of gases decreases with increasing temperature, the cold water will take up more CO2 and less will be escaping to the air. Furthermore, cold water is denser than warm water, causing it to sink.
Is the potential energy on the surface of Earth zero?If not,what will be it's value?
Answer:
Potential energy does not have an absolute measurement. It is always relative to some reference point. Gravitational potential always increases when you go up and decreases when you go down. But the choice of a zero point is arbitrary.
If you’re dropping objects onto the ground, then choosing the ground as a zero point makes the calculations easier. But you could just as easily make the zero point the top of Mt. Everest, and all the answers would turn out the same. Up still means more energy and down means less, but now the PE of an object at sea level would have a negative sign, but not as negative as an object ten meters above sea level.
So everything would still work fine.
In fact, planetary astronomers take this idea to extremes. Instead of the top of Mt. Everest, they set the zero point for potential energy as infinitely high—so far “up” that gravity is so weak that going “up” another kilometer doesn’t gain you any energy. Then the value for potential energy everywhere else in the universe anywhere near a planet has a negative sign, but just as before, all the answers in relative terms turn out fine.
Explanation:
PLEASE MARK ME AS BRAINLIEST
The internet is based on this concept of using optical fibers to send information.
True or False?
Answer:
False
Explanation:
The internet uses various mediums (fibre optic being only one of the newer ones) to transfer information.
An Olympic high diver (mass = 70 kg) stands on a platform 20 m above the surface of the water. What is the diver's gravitational potential energy?
Answer: 13720
Explanation: the equation is....
(70 kg) (9.8 m/[tex]s^{2}[/tex]) (20 m) = 13720A 50 kg child is sitting on a scale on the floor of an elevator. The elevator starts at rest and accelerates down at a rate of a=−1 m/s2.Calculate the velocity of the elevator after 3 seconds.
Answer:
v=m/s m=v.s -1*3= -3 meter/second
The velocity of the elevator after 3 seconds will be equal to 3 m/s.
What are equations of motion?We have three equations of motion that can be used to calculate components such as displacement(s), initial (u) and final velocity (v), time(t), and acceleration(a). The expressions for the three equations of motion are as follows:
First Equation of Motion :
v = u + at
Second Equation of Motion :
S = ut + (1/2) at²
The third equation of motion is:
v² - u² =2aS
Given, the initial velocity (u) of the elevator is zero as the elevator is at rest initially.
The acceleration of the elevator, a = -1 m/s² moving downward.
The final velocity of the elevator after 3 seconds will be:
v = u + at
v = (0) + (-1 m/s²) (3 s)
v = - 3 m/s
Therefore, the velocity of the elevator after 3 seconds will be equal to 3 m/s in the downward direction.
Learn more about the equations of motion, here:
https://brainly.com/question/16782759
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Kinetic energy increases as:
A. Mass increases and velocity decreases.
B. Mass decreases and velocity increases.
C. Both mass and velocity increase.
D. Both mass and velocity decrease.
Kinetic energy formula is: 1/2 mv^2
M = mass
V = Velocity
So as kinetic energy increases, mass increases and velocity increases because mass and velocity are directly proportional to each other.
The following are examples of physical properties EXCEPT ____.
color
density
shape
ability to react with oxygen
Answer:
ability to react with oxygen
Sam makes six star-shaped cookies out of dough. He puts all of the cookies on a balance and measures the total weight as 36 grams. He then squeezes the cookies into one big ball and measures the weight. What is the weight of the entire ball?
Answer:
The answer is "36 grams".
Explanation:
In this question, the weight of the ball is not mentioned but is the weight of the cookies is declared, which is equal to 36 grams, and all the cookies are squeezes into the ball and after that, it calculates the overall weight so, let assume that ball weight is =0 and then the overall weight is:
[tex]=\text{weight of ball + cookies weight}\\\\=0+36 \ grams \\\\=36 \ grams[/tex]
How are rechargeable batteries recharged? (site 1)
If a car with a mass of 5Kg, has a momentum of 25kgm/s, how fast is it travelling?
Answer:
5m/s
Explanation:
p=mv, or momentum (p) is equal to mass (m) times velocity (v).
so:
m=5Kg
p=25Kgm/s
v=p÷m
v=25÷5
v=5m/s
hoped this helped :)
Answer:
5hrs
Explanation:
Mass•Accelleration=Momentum (5kg•5hrs=25Mps)
Mass÷Momentum=Accelleration (25Mps÷5kg=5hrs)
A bullet (m = .005 kg) moving at 500 m/s strikes
and sticks in a block of wood (m = 5 kg). What is
the final velocity of the wood/bullet mass?
Answer:
fif = 0.01 x 5000 = 50 N
Explanation:
u=150 m/s
v=0
m-10 y =0.01 kg
t=0.03s
s
v=utat
o= 150+a (0.03)
therefore a= -5000 m/s power 2
v power 2 = u power 2 + 2as
0=150 power 2+ 2 x (-5000) x s
therefore f=2.25 m
please help me answer this
Answer:
W>R...............
Explanation:
.........................
Yes
You have five employees. They worked the following hours last week: 40, 37, 33, 25, 20. What was the mean number of hours worked?
Answer:
[tex]40 + 37 + 33 + 25 + 20 \div 5 = 155 \div 5 = 31[/tex]
Answer:
Or you could just say 31 :)
Explanation:
A bike travels at 120 meters in 60 seconds. What is the speed of the bike?
Answer:
2 m/s
Explanation:
Which element’s symbol could replace the question mark in the diagram? carbon (C) tellurium (Te) beryllium (Be) cesium (Cs)
Answer:
Tellurium
Explanation:
Answer:
Tellurium
Explanation:
a variable that is changed by the researcher is called ___
(c) What would the angle of reflection be if the incident ray
was 40° from the reflecting mirror surface?
Answer:
So, if a wave hits a mirror at an angle of 36°, it will be reflected at the same angle (36°). ... An incident ray of light hits a plane mirror at an angle and is reflected back off it. The angle of reflection is equal to the angle of incidence. Both angles are measured from the normal.
Explanation:
Please help!! I'll name you brainliest!!
Answer:
b
Explanation:
in this condition the atom is not stable so in order to become stable ( trying to have the last energy level completely filled like the Nobel gases) it tends to lose or gain or share the electrons and that debend on its condition . I hope that's the right answer