Answer:
1) combustion can be used as a source of energy.
Combustion is used to power rockets
ii) Decomposition of sugar is a chemical change and new substances are formed.
2)corrosion of pipes
Corrosion of bridges
Corrosion of knives and blades at home
I) iron rusts due to the action of air and moisture bon the metal setting up an electrochemical process in which the iron is the anode. This leads to the corrosion of the iron metal.
ii) Rusting is a problem because it reduces the economic value of iron. Rust weakens iron and threatens the integrity of materials made from iron.
Iron rusting may lead to the collapse of a bridge
Iron rusting makes a blade blunt
Iron rusting weakens pipes made of iron
iii) Rusting of iron can be prevented by galvanizing the iron or by painting the iron.
3) chemical change leads to the formation of a new substance while physical change does not lead to the formation of a new substance.
Chemical changes are not easily reversible while physical changes are easily reversible.
ii)condensation of water vapour is a physical change
iii)
Electrolysis of water;
Two moles of water---> two moles of hydrogen gas + one mole of oxygen gas
Synthesis of water;
two moles of hydrogen gas + one mole of oxygen gas---->Two moles of water
Decomposition of sugar;
One mole of Sucrose---> twelve moles of carbon + eleven moles of water + heat
Six moles of carbon dioxide + six moles of water +energy------> one mole of sugar + six moles of oxygen
Explanation:
Combustion is useful as a source of energy because it is used in power generation. Currently, combustion is being used to power rockets. It is also used as a way of providing heat at home.
One of the characteristics of a chemical change is that it leads to the formation of new substances. Since the decomposition of sugar leads to the formation of carbon and water, it is an irreversible chemical change.
When water is heated, it is converted into vapour which can settle on a surface and convert back to liquid water. This is a physical change.
A 31.7 kg kid, initially at rest, slides
down a frictionless water slide at 53.2º.
How fast is she moving 3.45 s later?
Answer:
34.55m/s
Explanation:
Now from Newton's law of motion;
V= U+ a×t
V- final velocity
U- initial velocity = 0m/s
a- acceleration
t- time
Note that a = g/cos53.2°
Now g is acceleration of free fall due to gravity
This is a vertical acceleration since the course of motion is along a plane inclined at 53.2° to the height of the pool.
Also from trigonometry identity
cos 53.2°= vertical component a/ acceleration ( cos a = adjacent/hypothenus)
If we assume g = 9.8m/S2 { a generally given value}
Substituting t = 3.45s as the time of consideration, we have;
V = 0 + (9.8/cos53.2°)×3.45
= -34.55m/s
Note the -ve sign is just telling us this velocity is causing the object to move down.
Hence V = 34.55m/s
Answer:
27.07 m/s
Explanation:
this is the right answer
What observation about light supported Einstein’s theory?
Answer:
Explanation:
Do you mean the theory that space-time is defined by what's in it? And that mass warps space-time?
There are many instances where his observation turned out to be correct. The most popular one is the phenomena of gravitational lensing. We can see the light from stars that are actually behind the sun. The huge gravity of the sun bends space-time and this also bends light. We use gravitational lensing alllll the time when trying to see very distant stars or galaxies.
Answer:
The Sun bent the light from a star. This bending made the star appear in a slightly different position from its actual position. This observation supported Einstein’s theory.
Explanation:
This is the answer on Edmentum! :)
PLEASE HELP!!!!!
When describing image formation for plane mirrors, what is an important rule
to remember about light rays?
Answer: The image formed by a plane mirror is always virtual (meaning that the light rays do not come from the image), upright and of the same shape and size as the object it is reflecting.
Answer: B. The angle when it leaves is the same as the angle when it hits
Explanation:
Apex
I NEED ANSWER RN OR ILL BE DED
Answer:
i) O m/s² as velocity is constant
ii) 20m/s
iii)Hint:Calculate the area of the graph,that is;below the line, for the first 15 seconds only
Hope this helps.
Which two laws were discovered by Antoine Lavoisier and Joseph Proust
Answer:
Joseph proust's law of difinite composition
Law of conservation of mass
Explanation:
Dalton's law of multiple proportions is part of the basis for modern atomic theory, along with Joseph Proust's law of definite composition (which states that compounds are formed by defined mass ratios of reacting elements) and the law of conservation of mass that was proposed by Antoine Lavoisier.
Answer:
law of conservation of mass
law of definite proportions
Explanation:
when scientists publish experimental results their results are often criticized by other scientists how is this process a source of strength of Science? It encourages scientists to give convincing evidence for the results
it allows scientists to keep their data secret
a scientific model is not used full unless everyone thinks it's true
or if forces scientists to publish results that are in line with current theories
Answer: It encourages scientists to give convincing evidence for the results
Answer:
A.) would be the right answer
Explanation:
I took the test :)
What is the wavelength of a 1.28 x 10^17 Hz wave?
Answer:
The wavelength of the wave is 2.34 nm.
Explanation:
It is required to find the wavelength of a [tex]1.28\times 10^{17}\ Hz[/tex] wave. A wave moves with a speed of light. Speed of a wave is given in terms of wavelength and frequency. So,
[tex]v=f\lambda[/tex]
[tex]\lambda=\dfrac{c}{f}\\\\\lambda=\dfrac{3\times 10^8}{1.28\times 10^{17}}\\\\\lambda=2.34\times 10^{-9}\ m\\\\\text{or}\\\\\lambda=2.34\ nm[/tex]
So, the wavelength of the wave is 2.34 nm.
The wavelength of the wave is 2.34 × 10⁻⁹ meters.
Given the data in the question;
Frequency; [tex]f = 1.28*10^{17}Hz[/tex]Wavelength; [tex]\lambda =\ ?[/tex]
To determine the wavelength of the wave, we use the expression for the relations between wavelength, frequency and speed of light.
[tex]\lambda = \frac{c}{f}[/tex]
Where [tex]\lambda[/tex] is wavelength, f is frequency and c is speed of light ( [tex]3*10^8m/s[/tex] )
We substitute our values into the equation
[tex]\lambda = \frac{3*10^8m/s}{1.28*10^{17}Hz} \\\\\lambda = \frac{3*10^8m/s}{1.28*10^{17}s^{-1}} \\\\\lambda = 2.34 * 10^{-9}m[/tex]
Therefore, the wavelength of the wave is 2.34 × 10⁻⁹ meters.
Learn more: https://brainly.com/question/10674607
Why will a delivery truck filled with birds sitting on its floor be heavier than a truck with the same birds flying around inside.
The reason why a delivery truck filled with birds sitting on the floor be heavier than a truck with the same birds flying around is because when the birds are sitting on the floor, they are adding their weight to the truck.
Meanwhile, if the birds are flying around they aren't resting on the truck or touching it, so therefore their weight wouldn't be added to the truck.
The mass of the truck will remain the same as you cannot change the mass but the weight will vary depending on the items and objects placed in it.
Please LOTS OF POINTS. WILL MARK BRAINLIEST
Calculate the Resulting movement using the formula:
Perpendicular distance x Force
1]F1*D1=F2*D2
10N×2m=5N*3m
20N=15Nm
The seesaw will turn anti clock wise.
2]
F1*D1=F2*D2
3N*4m=2N*6m
12Nm=12Nm
It will neither rotate toward anti clock wise nor clock wise
Ahoy starting from rest moves with a distance of 200m in 10 seconds...Find the magnitude of acceleration
Answer:
The magnitude of acceleration is 2m/s² .
Explanation:
First, you have to find the velocity as it starts to travel 200m in 10s. The formula of velocity is V = Distance/Time, then you have to substitute the values into the formula :
[tex]v = d \div t[/tex]
[tex]let \: d = 200 \\ let \: t = 10[/tex]
[tex]v = 200 \div 10[/tex]
[tex]v = 20m/s[/tex]
Next, you have to substitute the values into the acceleration formula, a = (v-u)/t where v represents final velocity, u is initial velocity and t is time taken :
[tex]a = \frac{v - u}{t} [/tex]
[tex]let \: v = 20 \\ let \: u = 0 \\ let \: t = 10[/tex]
[tex]a = \frac{20 - 0}{10} [/tex]
[tex]a = \frac{20}{10} [/tex]
[tex]a = 2m/ {s}^{2} [/tex]
Julie is cycling at a speed of 3.4 meters/second. If the combined mass of the bicycle and Julie is 30 kilograms, what is the kinetic energy?
A.
1.7 × 102 joules
B.
1.5 × 102 joules
C.
2.0 × 102 joules
D.
2.2 × 102 joules
Answer:
A
Explanation:
KE = 1/2 mv^2
=1/2(30kg)( 3.4 m/s)^2
=173.4 joules
=1.7×10^2 joules
A squeeze bottle squeezes when pressed. It regains its shape when pressed .It regains its shape when the pressure from your hand is withdrawn. What may happen if the squeeze bottle is pressed to take the sauce out and then immediately corked tightly? Will it regain its shape? If not, Why?
Answer: It will not regain its shape, because when it is corked it can not replace the volume of material that you just take out of it.
Explanation:
When you squeeze the bottle, you are changing the volume of the bottle, in this process, you are "expelling" the material inside the bottle.
When you stop squeezing, there is a change in pressure, and the bottle "absorbs" air, until the pressure is equilibrated, and in this process, the bottle returns to the original shape.
Now, if you take the sauce out of the bottle and immediately cored it, then you removed the material inside of the bottle and did not let the bottle to "refill" the empty space with air, so it can not regain its shape.
would iron and carbon form metallic bonds
Answer:
NO.
Explanation:
METALLIC BOND IS ONLY IN METALS.
Since iron is a metal and carbon a non- metal, they cannot form a metallic bond.
Which of the following is an example of Newton's Third Law of Motion?
a. a person sliding to the right as a car turns left
b. a boy pulling a sled
c. gasses pushing a rocket forward
d. a hockey puck sliding across the ice
Answer:
C. gasses pushing a rocket forward
Explanation:
the fireball___ ___when moving___
Answer:
the fireball flamed dangerously when moving quickly
Explanation:
im prbly wrong idk
The graphic organizer compares energy transfer in two layers of the Sun. A venn diagram of 2 intersecting circles with the left circle labeled convection zone and the right circle labeled radiative zone. There is an X in the convection zone circle. There is a Y in the radiative zone. Which labels belong in the regions marked X and Y? X: Absorbs energy from the core Y: Takes longer for photons to move through X: Releases energy to the photosphere Y: Takes longer for photons to move through X: Takes longer for photons to move through Y: Absorbs energy from the core X: Takes longer for photons to move through Y: Releases energy to the photosphere
Answer:
X: Absorbs energy from the core.
Y: Releases energy to the photosphere.
Explanation:
Convection is a mode of heat transfer through fluids (liquids or gas), and it requires material medium for its propagation.
The energy absorbed from the core of the Sun, is transferred through X (convection zone) by convectional process, and it flows to Y (radiative zone). Since the regions X and Y have different functions, the heat propagates from X causing photons to traverse through Y where it get released into the photosphere or the Sun's surface.
Therefore;
X: Absorbs energy from the core.
Y: Releases energy to the photosphere.
Answer:
X: Takes longer for photons to move through
Y: Releases energy to the photosphere
Explanation:
4 answers. Anyone know?
Answer:
lift
weight
thrust
air resistance
Explanation:
plz mark me as brainliest
Answer: Upthrust, lift, air resistance, and thrust
Explanation:
All of these 4 elements are taken into account during the design and creation of a plane.
1. How many digits does the frog have on each of its forelegs and how many on each of its
hind legs?
Answer:
A frog has four digits on its fore legs
A frog has five digits on its hind legs
Explanation:
Biologically, digits refer to the fingers and toes of animals (mostly vertebrates).
A frog is known to have only four digits on its fore limbs (which are not webbed). They usually use this for steering themselves in the water.
A frog also has five digits on each of its hind legs. These are webbed, and are used for swimming in water.
what is web browser
Answer:
A web browser is a software application for accessing information on the World Wide Web
Answer:
web browser (commonly referred to as a browser) is a software application for accessing information on the World Wide Web. When a user requests a web page from a particular website, the web browser retrieves the necessary content from a web server and then displays the page on the screen.
Explanation:
An object is placed at 1.5 m from a convex lens with a focal length of 1.0 m.
a. Use the thin lens equation to determine the image distance from the lens.
b. If the object height is 2.0 m, what is the image height?
c. Is the image real or virtual? Is the image inverted or upright?
A ball is being rolled by a normal push of 1000N. it is opposed by friction which has a force of 0.3kN and air resistance which has a force of 23N. Calculate the resultant force.
Answer:
677 N
Explanation:
Let F = normal push force = 1000 N, f = frictional force = 0.3 kN = 300 N and f' = air resistance = 23 N.
Since the frictional force and the air resistance are in the opposite direction the the normal push force, the resultant force R is
R = F - f - f'
= 1000 N - 300 N - 23 N
= 677 N
A ramp is a simple machine called the
a. wedge
b. pulley
c. inclined plane
d. lever
Answer:
Inclined Plane is the answer
Answer:
Inclined plane
Explanation:
It is called Inclined plane since it is a flat surface at an angle.
write the different between the fall of a parachute on earth and its fall on the moon?on what condition does a body have free fall?
Answer:
Shown from explanation
Explanation:
You have heard that expression what ever goes up must come down that's usually used to mean when you throw an object up, it comes down on its accord. This is due to a force on the earth that occurs in nature known as gravity.
So when an object falls under this influence it's said to fall freely.
Note not all heavenly bodies have gravitational pull, from experience by scientists who went to the moon they found out whatever goes up keeps flying endlessly so in that case an external force is needed to keep objects in the moon on ground level.
Hence the parachute falls on earth freely without an external force but on the moon it must fall with an external force inputed on the parachute system.
This means in the earth we have free fall but in the moon no such thing exist. So a body falls freely when there is gravity.
A scanning tunneling microscope is used to measure small changes in height of a surface by detecting changes in the tunneling current between the tip and the surface. The current is proportional to the tunneling coefficient (ie. I = const * T) which follows the general equation for tunneling through a square well , with C dependent on the molecule and L is the distance. The transmission coefficient at one point is T = 0.01, what is the relative current if the distance is increased from L to 5L? We are interested in I(5L)/I(L). (Note: there may be more information provided than you need to solve the problem.)
Answer:
[tex]\mathbf{\dfrac{I(5l)}{I(l) } =10^{-8}}[/tex]
Explanation:
We are being told that the current is proportional to the tunneling coefficient[tex]I(l) = I_0 e^{-2kl}[/tex] ;
where l = distance between the tip and the surface.
Let [tex]I(l) = I_0 e^{-2kl}[/tex] ------------ equation (1)
and [tex]I(5l) = I_0 e^{-2k(5l)}[/tex] ------------ equation (2)
Dividing equation (2) by (1); we have :
[tex]\dfrac{I(5l)}{I(l) } = \dfrac{I_0 e^{-2k(5l)}}{ I_0 e^{-2kl}}[/tex]
[tex]\dfrac{I(5l)}{I(l) } =e^{-2k(5-1)l}[/tex]
[tex]\dfrac{I(5l)}{I(l) } =(e^{-2kl})^4[/tex]
where ;
[tex](e^{-2kl})[/tex] represents the transmission coefficient T = 0.01
Thus; replacing the value for 0.01;we have;
[tex]\dfrac{I(5l)}{I(l) } =0.01^4[/tex]
[tex]\mathbf{\dfrac{I(5l)}{I(l) } =10^{-8}}[/tex]
state two factors that affect the turning effect of force
Answer:The first is the magnitude of the force applied on the body and the second is the perpendicular distance from the line of action of force and the axis of rotation of the body.
Explanation:
can someone put these in the right order please
You get in your car to drive to school at 7:33 am and drive 10 miles north at a constant speed until 7:45
am, when you realize you left your homework on the kitchen table. You turn around and drive 10 miles
south back to your house and retrieve your homework at 8:00 am. You get back in the car and drive 15
miles north to school at a constant speed arriving at school at 8:29 am sharp, just in time to make it
before the bell rings.
e
Answer:
5.) 16.8 m/s
6.) 16.1 mph
7.) Moving fast.
Explanation:
5.) From the question, the total time will be:
7:33 am to 7:45 am = 12 minutes
As the car turns around,
7 : 45 am to 8 : 00am = 15 minutes
As you get back in the car and drive 15
miles north to school at a constant speed arriving at school at 8:29 am
8:00am to 8:29 am = 29 minutes
Total time = 12 + 15 + 29 = 56 minutes
Convert the minutes to second by multiplying the result by 60
Total time = 56 × 60 = 3360 seconds
Total distance covered will be
10 miles + 10 miles + 15 miles = 35 miles
Convert mile to meter by multiplying the result by 1609.344
35 × 1609.344 = 56327.04
Speed is a scale quantity. It only involves magnitude but no direction.
Average speed = total distance/total time
Average speed = 56327.04/3360
Average speed = 16.764 m/s
6.) Velocity = displacement/time
Velocity is a vector quantity. We will consider both the magnitude and direction
Total displacement = 10 miles - 10 miles + 15 miles = 15 miles.
Total time = 56 minutes
Convert minutes to hours by dividing it by 60
Total time = 56/60 = 0.93 hours
Substitute the time and displacement into the formula
Velocity = 15/0.93 = 16.07 mph
7.) . If you looked at your speedometer on your drive to school and it read 30mph, this value describes you move with a fast speed.
Help what is the answer
Answer:
C
Explanation:
[tex]F=k\dfrac{Q_1Q_2}{r^2}= \\\\(8.99 \times 10^9)\dfrac{(-2\times 10^{-4})(8\times 10^{-4})}{0.3^2}\approx 1.6\times 10^4 N[/tex]
Hope this helps!
A train takes 2h to reach station B from station A and 3h to return back to A.The distance between the station is 200km, then its average speed would be
Answer:
80km/hr
Explanation:
Total distance: 400km
Total time 5 hours
Average speed= distance/time
400/5= 80km/hr
explain why atmospheric pressure decreases towards higher altitudes
Answer:
At higher elevations, there are fewer air molecules above a given surface than a similar surface at lower levels. ... Since most of the atmosphere's molecules are held close to the earth's surface by the force of gravity, air pressure decreases rapidly at first, then more slowly at higher levels.
Explanation:
happy to help:)
