Answer:
D. The air we breathe is a homogeneous mixture because it has substances but the same appearance throughout.
Explanation:
The air we breathe is a homogeneous mixture.
Air is a mixture of many gases. A homogeneous mixture is one whose constituents exists in one phase.
Air is a gas - gas mixtures.
A mixture has indefinite composition. They consist of two or more elements and or compounds in any proportion by mass.
Constituents retain their identities i.e. physical properties are retained.
A 70 kg object strikes the ground with 2500 J of KE after falling freely from rest. How far above the ground was the object when it was released?
Answer:
3.64 m
Explanation:
m = Mass of object = 70 kg
Kinetic energy of the object = 2500 J
g = Acceleration due to gravity = [tex]9.81\ \text{m/s}^2[/tex]
h = Height from which the object is dropped
Kinetic energy is given by
[tex]\dfrac{1}{2}mv^2=2500\\\Rightarrow v^2=\dfrac{2\times 2500}{70}[/tex]
From conservation of energy we get kinetic energy equal to potential energy.
[tex]\dfrac{1}{2}mv^2=mgh\\\Rightarrow h=\dfrac{1}{2g}v^2\\\Rightarrow h=\dfrac{1}{2\times 9.81}\times \dfrac{2\times 2500}{70}\\\Rightarrow h=3.64\ \text{m}[/tex]
The object was released from a height of 3.64 m.
a substance has a pH of 9.what type of substance is it
Answer:
I think its Baking soda, antacids, Sorry if i'm wrong!
Explanation:
Answer:
it base
Explanation:
because i passed the test on that
1) If Shagreen bought the energy star refrigerator for $1800 and saved
$200 every year, how many years would it take for her to save back the
money she spent on the refrigerator?
Answer:
9
Explanation:
Shagreen bought the energy star generator for $1800
She saves $200/every year
Therefore the number of years it would take for her to save that amount can be calculated as follows
= 1800/200
= 9
Hence it would take 9 years to save up the money
Definition of dispersal
Answer:
the action or process of distributing things or people over a wide area.
"the dispersal of people to increasingly distant suburbs"
the splitting up of a group or gathering of people, causing them to leave in different directions.
"the dispersal of the crowd by mounted police"
the splitting up and selling off of a collection of artifacts or books.
"the dispersal of the John Willett Collection"
Explanation:
Does the KE of a car change more when it accelerates from 22 km/h to 32 km/h or when it accelerates from 32 km/h to 42 km/h
Answer:
The change in kinetic energy (KE) of the car is more in the second case.
Explanation:
Let the mass of the car = m
initial velocity of the first case, u = 22 km/h = 6.11 m/s
final velocity of the first case, v = 32 km/h = 8.89 m/s
change in kinetic energy (K.E) = ¹/₂m(v² - u²)
ΔK.E = ¹/₂m(8.89² - 6.11²)
= 20.85m J
initial velocity of the second case, u = 32 km/h = 8.89 m/s
final velocity of the second case, v = 42 km/h = 11.67 m/s
change in kinetic energy (K.E) = ¹/₂m(v² - u²)
ΔK.E = ¹/₂m(11.67² - 8.89²)
= 28.58m J
The change in kinetic energy (KE) of the car is more in the second case.
A satellite is launched to orbit the Earth at an altitude of 2.25*107 m for use in the Global Positioning System (GPS). Take the mass of the Earth to be 5.97*1024 kg and its radius 6.38*106 m.
What is the orbital period of this GPS satellite?
Answer:orbital period of this GPS satellite, T= 48,874.4 s
Explanation:
Altitude (h)= 2.25 X 10^7 m
Radius of the Earth ( r)=6.38 X 10^6 m
The distance from center of the Earth to the point is given as
R = r +h
6.38 x 10^6 m+ 2.25 x 10^7 m
=28,880,000=2.888 x 10^7m
Also, Mass of the Earth =5.97 x 10^24 kg
and Gravitational Universal Constant
= 6.67 x 10^-11N.m2/kg2
Orbital period T
= 2π
=2 X 3.142[tex]\sqrt{ (2.888 x 10^7m)^3 /6.67 x 10^-11N.m2/kg2 X 5.97 x 10^24 kg}[/tex]
2X 3.142 [tex]\sqrt{60,491088.9}[/tex]
= 2X 3.142 X 7,777.60
T= 48,874.4 s
An airplane normally flying 80km/h north encounters a wind from the west of 10km/h at a right angle to its forward motion a crosswind what will it's resultant velocity be?
Answer:
Resultant velocity of the airplane = 80.62 km/h
Explanation:
Given that,
An airplane normally flying at 80 km/h north encounters a wind from the west of 10km/h at right angle to its forward motion a crosswind.
We need to find the resultant velocity of the airplane. It can be calculated as follows :
[tex]v=\sqrt{80^2+10^2} \\\\v=80.62\ km/h[/tex]
So, the required velocity is 80.62 km/h.
Eating 2500 Cal every day a friend of mine maintains a stable weight of 70 kg. One day, after eating 3500 Cal, he decided to do extra exercise to avoid gaining weight. He was doing jumps: he leaves the ground with a speed of 3.3m/s at every jump. Assuming that his body turns energy to mechanical work with a 25 % efficiency, how many jumps he will have to make
Answer:
2721
Explanation:
First, we find the change in calories
E = E(taken) - E(daily)
E = 3500 - 2500
E = 1000 cal
Next, we use the efficiency to find the available metabolic energy
E' = n.E, where n = efficiency
E' = 0.25 * 1000
E' = 250 cal
Converting this cal to J, we have
1 cal = 4.18 J
250 cal = 250 * 4.18 J
250 cal = 1045 kJ
Given that the final velocity is 0, we use equation of motion to find the height, h attained
u² = 2gh
h = u²/2g
h = 3.3² / 2 * 9.81
h = 10.89 / 19.62
h = 0.56 m
Potential energy, E = mgh
E = 70 * 9.8 * 0.56
E = 384 J
Total number of jumps, n =
n = 1045 / 384
n = 2721 jumps
A 235 kg crate is pulled across a horizontal surface with a force of 760 N applied at an
angle of 30° above the horizontal. Determine the horizontal component of the applied
force
Answer:
658.16N
Explanation:
Step one:
given data
mass m= 235kg
Force F= 760N
angle= 30 degrees
Required
The horizontal component of the force
Step two:
The horizontal component of the force
Fh= 760cos∅
Fh=760cos30
Fh=760*0.8660
Fh=658.16N
Does the voltage of a battery affect the strength of an electromagnet?
I'm trying to make an electromagnet that's strength is constantly getting incremented by small amounts every second. I need to know, which would have a greater effect on the electromagnet's strength, amps or volts? (I know increasing the turns and/or density of the magnet wire will increase the strength, but I am looking for answers other than that particular one.)
If the melanin lines on the wing are spaced 2.0 μm apart, what is the first-order diffraction angle for green light (λ = 550 nm)?
This question is incomplete, the complete question is;
The wings of some beetles have closely spaced parallel lines of melanin, causing the wing to act as a reflection grating. Suppose sunlight shines straight onto a beetle wing.
If the melanin lines on the wing are spaced 2.0 μm apart, what is the first-order diffraction angle for green light (λ = 550 nm)?
Answer:
the first-order diffraction angle for green light is 15.96°
Explanation:
Given the data in the question;
from diffraction theory;
nλ = dsin∅
where n is the diffraction order ( 1st order = 1 )
λ is the wavelength ( 550 nm = 550 × 10⁻⁹ m)
d is the grating spacing ( 2.0 μm = 2.0 × 10⁻⁶ m )
∅ is the diffraction angle ( ? )
so we substitute
nλ = dsin∅
sin∅ = nλ / d
sin∅ = (1 × 550 × 10⁻⁹ m) / 2.0 × 10⁻⁶ m
sin∅ = 0.275
∅ = sin⁻¹(0.275)
∅ = 15.96°
Therefore, the first-order diffraction angle for green light is 15.96°
A pitcher throws a 0.143-kg baseball toward the batter so that it crosses home plate horizontally and has a speed of 42 m/s just before it makes contact with the bat. The batter then hits the ball straight back at the pitcher with a speed of 49 m/s. Assume the ball travels along the same line leaving the bat as it followed before contacting the bat. If the ball is in contact with the bat for 0.005 0 s, what is the magnitude of the average force exerted by the bat on the ball?
Answer:
200N appox
Explanation:
Step one:
Given data
mass of ball= 0.143kg
initial velocity of ball u= 42m/s
final velocity of the ball= 49m/s
time of impact= 0.005s
Step two
From the relation Ft=mΔv
we can find the average force as
F=mΔv/t
substitute
F=0.143*(49-42)/0.005
F=0.143*7/0.005
F=1.001/0.005
F=200.2
F= 200N appox
The average force is 200N
Match each word to its correct meaning.
1. humus
the thin upper layer of Earth's crust that supports plant life
2. inorganic
a vertical section of soil that shows the horizon and parent material
3. organic
the layer of loose rock on the surface of the earth; also called mantle rock
4. parent material
dark colored organic material in soil; it is left over from the decay of living things
5. regolith
a physical property of soil that describes how the soil feels, and the relative components of sand, silt, and clay sized particles
6. soil
a chemical property of soils that describes the measure of hydrogen ions in a soil sample; how acidic or basic a soil sample is
7. soil horizon
a substance that does not contain carbon and hydrogen atoms, such as salts, rocks, and minerals
8. soil ph
a distinct layer of soil that has characteristic properties
9. soil profile
the rock material that was weathered to form the sediments in a given soil
10. soil texture
a substance that contains carbon and hydrogen atoms, such as carbon dioxide, glucose, methane, and nucleic acid
Answer:
1. Soil.
2. Soil profile.
3. Regolith.
4. Humus.
5. Soil texture.
6. Soil pH.
7. Inorganic.
8. Soil horizon.
9. Parent material.
10. Organic.
Explanation:
1. Soil: the thin upper layer of Earth's crust that supports plant life. There are three (3) main types of soil; sandy, clay and loamy soil.
2. Soil profile: a vertical section of soil that shows the horizon and parent material.
3. Regolith: the layer of loose rock on the surface of the earth; also called mantle rock.
4. Humus: dark colored organic material in soil; it is left over from the decay of living things.
5. Soil texture: a physical property of soil that describes how the soil feels, and the relative components of sand, silt, and clay sized particles.
6. Soil pH: a chemical property of soils that describes the measure of hydrogen ions in a soil sample; how acidic or basic a soil sample is.
7. Inorganic: a substance that does not contain carbon and hydrogen atoms, such as salts, rocks, and minerals.
8. Soil horizon: a distinct layer of soil that has characteristic properties.
9. Parent material: the rock material that was weathered to form the sediments in a given soil.
10. Organic: a substance that contains carbon and hydrogen atoms, such as carbon dioxide, glucose, methane, and nucleic acid.
a tool for studying motion is called?
Answer:
phytochemical
Explanation:phytochemical is a tool for studying motion
Amateur radio operators in the United States can transmit on several bands. One of those bands consists of radio waves with a wavelength near 15.m. Calculate the frequency of these radio waves. Round your answer to 2 significant digits.
Answer:
20 MHz
Explanation:
Since speed of radio waves = speed of light = c and for a wave, v = fλ where v = speed of wave, f = frequency and λ = wavelength.
Given that λ = 15 m and v = c = 3 × 10⁸ m/s
f = v/λ
substituting the values of the variables into the equation, we have
f = v/λ = 3 × 10⁸ m/s ÷ 15 m
= 0.2 × 10⁸ Hz
= 2 × 10⁷ Hz
= 20 × 10⁶ Hz
= 20 MHz
A quantitative review of the health record for missing reports and signatures that occurs when the patient is in the hospital is referred to as a review
Answer: This is referred to as a Concurrent review.
Explanation:
A health records of a patient consists of the medical history, diagnosis, treatment and even laboratory test results which provides reasonable information for health providers to make decisions about a patient's care.
A quantitative review of these health records are carried out by trained professionals to have a clear view of everything that has occurred previously to the patient and to know the extent of current injury or illness.
A quantitative review of these records can be:
--> Retrospective or
--> Concurrent.
Retrospective record review is carried out when the patient has left the hospital facility. This is used to supplement the concurrent record review to ensure a complete data set for performance measurement purposes.
Concurrent record review is carried out when a patient is hospitalised or undergoing active treatment. This review helps to obtain missing information or reports about the patient. The advantage of concurrent record review is the ability to easily initiate interventions when problems are identified as the patient is still in the facility.
What causes the movement of electrical current in the circuit within the device shown in the diagram?
NASA
Movement of protons
Movement of electrons
Heating of silicon
The anti-reflection coating
Answer:
B. Movement of electrons
Hope this helps!! may I have brainliest? :)
Answer:
Movenment of electrons
Explanation:
A woman of mass 50 kg is swimming with a velocity of 1.6 m/s. If she stops stroking and glides to a stop in the water, what is the impulse of the force that stops her?
Answer:
– 80 Ns.
Explanation:
From the question given above, the following data were obtained:
Mass (m) = 50 kg
Initial velocity (u) = 1.6 m/s
Final velocity (v) = 0 m/s
Impulse (I) =?
Impulse is simply defined by the following equation:
I = Ft = m(v – u)
I = 50 (0 – 1.6)
I = 50 (–1.6)
I = – 80 Ns
Thus, the impulse of the force that stopped her is – 80 Ns.
NOTE: The negative sign indicates that the net force is in opposite direction to her movement.
A generator transforms?
What is the electric field inside a hollow sphere with total charge Q distributed evenly along the surface of the sphere
Answer:
0 N/C
Explanation:
Using Gauss' law ∫εE.dA = Q. where E = electric field, dA = differential area and Q = charge enclosed.
Since for r < r₀ where r₀ = radius of the sphere, Q = 0. and ∫εE.dA = ∫εEdAcos180 (since the electric field is directed radially inward opposite to the normal area vector)
∫-εEdA = 0
-εE∫dA = 0
-εEA = 0
E = 0/-εA
E = 0 N/C
Two firefighters are trying to break through a door. One firefighter is heavy, and the other is light. If they run at the same speed, which one is more likely to break through? Explain.
Answer:
The Heavier Firefighter
Explanation:
Generally, more massive objects will have more intertia than less massive objects. As such it takes more force to halt a more massive object if its moving at the same speed as a smaller object. This can also be thought of in the context of Newton's second law. The more force needed to accelerate an object means the more force the object will have.
At equal speed, the firefighter with more weight will have more momentum and exact more force which will cause breakthrough.
According to Newton's second law of motion, the force applied to an object is directly proportional to the product of mass and acceleration of the object.
F = ma
Acceleration is the change in velocity per change in time of motion.
The law can also be written as;
[tex]F = ma = \frac{mv}{t}[/tex]
Also, momentum is given as the product of mass and velocity.
P = mv
Thus, at equal speed, the firefighter with more weight will have more momentum and exact more force which will cause breakthrough.
Learn more here:https://brainly.com/question/19275860
Activity
Many characters portrayed in the media suffer from psychological disorders. For example, piglet from Winnie the Pooh has generalized anxiety
disorder and Elsa from the movie Frozen has agoraphobla. Similarly, Identify at least four characters from movies or television shows and
describe the disorders the characters suffer from in the stories.
Answer:
Explanation:
Belle from beauty and the beast has what they call Stockholm syndrome.
Spongebob from Spongebob square pants has what is called Williams-Beuren syndrome
Ariel from the Little Mermaid has what they call Disposophobia.
Alice from Alice in the wonderland has what is called schizophrenia
Scar from the Lion King has what is known as anti social personality disorder.
Like the question suggested, many characters suffer different types of disorder, and I've just listed out a few
How does work done on an object affect its kinetic energy
According to the work-energy theorem, the work done on an object by a net force equals the change in kinetic energy of the object. Essentially kinetic energy is the energy used for motion. Interestingly, as work is done on an object, potential energy can be stored in that object. A moving object has kinetic energy because work has been done on it. When work is done energy in one form is transferred to the kinetic energy of the moving object. To stop the object again, the same amount of work would have to be done to bring it back to rest.
how many times can the earth revolve around the sun in the time it takes Jupiter to revolve around the sun once?????????
Answer:
Jupiter fully revolves around the sun in about 11.9 Earth years, where as Earth fully revolves around it in a year.
Explanation:
what causes dispersion of light?
Tim, with mass 73.1 kg, climbs a gymnasium rope a distance of 4.6 m. The acceleration of gravity is 9.8 m/s 2 . How much potential energy does Tim gain? Answer in units of J.
Answer:
3,295.348Joules
Explanation:
Potential Energy = mass * acceleration due to gravity * height
Given the following
Mass = 73.1kg
Acceleration due to gravity = 9.8m/s²
Distance (Height) = 4.6m
Substitute into the formula;
Potential Energy = 73.1 * 9.8 * 4.6
Potential Energy = 3,295.348Joules
Hence Tim gain 3,295.348Joules of energy
A wave is described by y(x,t) = 0.1 sin(3x + 10t), where x is in meters, y is in centimeters and t is in seconds. The angular wave number is:
Answer: 3 radians/meter.
Explanation:
The general sinusoidal function will be something like:
y = A*sin(k*x - ω*t) + C
Where:
A is the amplitude.
k is the wave number.
x is the spatial variable
ω is the angular frequency
t is the time variable.
C is the mid-value.
The rule that we can use to solve this problem, is that the argument of the sin( ) function must be in radians (or in degrees)
Then if x is in meters, the wave-number must be in radians/meters, so when these numbers multiply the "meters" part is canceled.
Then for the case of the function:
y(x,t) = 0.1 sin(3x + 10t)
Where x is in meters, the units of the wave number (the 3) must be in radians/meters. Then the angular wave number is 3 radians/meter.
Angular wave number is measured in rad/s. the angular wave number in the given equation is 10 rad/s.
Angular wave number:
It is the number of wavelengths per unit distance. It is also known as angular frequency. It is measured in rad/s.
For given equation,
[tex]\bold{y(x,t) = 0.1 sin(3x + 10t)}[/tex]
Angular wave number is the parameter which is multiplied by time (t). So, it is the number 10, this will be measured in rad/s.
Therefore, the angular wave number in the given equation is 10 rad/s.
To know more about angular wave number, refer to the link:
https://brainly.com/question/14668383
Drag the tiles to the correct boxes to complete the pairs.
Identify the type of potential energy described.
Tiles
gravitational
chemical
magnetic
elastic
electric
Answer:
those are all correct. The arrows are matched correctly
A marksman holds a rifle with a mass of 2.57 kg loosely, so it can recoil freely. He fires a bullet with a mass of 3.65 g horizontally with a velocity relative to the ground of 318.4 m/s. What is the final kinetic energy in J of the rifle
Answer:
KE = 0.262 J
Explanation:
given data
rifle with mass Mr = 2.57 kg
bullet with mass Mb = 3.65 g
velocity relative to the ground Vb = 318.4 m/s
solution
we get here final KE of rifle that is express as
KE = 0.5 × Mr × (Vr)² ..............1
here Vr is
Mb × Vb = Mr × Vr .........2
put here value
3.65 × [tex]10^{-3}[/tex] × 318.4 = 2.57 × Vr
Vr = 0.452 m/s
now put value in eq 1 we get
KE = 0.5 × 2.57 × (0.452)²
KE = 0.262 J
I need help, please.
Answer:
sorry I don't know it
Explanation:
