Answer:
B and D
Explanation:
Did the quiz
Electromagnetic waves require no wires to carry information and can travel through either air or other types of matter. Therefore, options (B) and (D) are correct.
What are electromagnetic waves?Electromagnetic radiations are produced when an electric field comes in contact with the magnetic field. Electromagnetic waves are the composition of oscillating electric as well as magnetic fields.
Infrared radiation is used in security cameras and used for night vision. UV rays are useful to detect forged banknotes as the real banknotes don’t turn fluorescent under UV light.
Electromagnetic radiation can travel energy in a vacuum or air. Electromagnetic waves play a vital role in today's communication technology. Electromagnetic waves are specially used in RADARS to detect aircraft in the earth's atmosphere.
Radio waves, microwaves, infrared (IR), and visible light can be used for communication. Radio waves are used to transmit information on television and radio programs. Microwaves are used to transmit satellites, mobile phones, and television.
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What force is responsible for crushing or collapsing stars?
O nuclear fusion
O gravity
energy
O forces
Answer:
Explanation:
Gravity is the correct answer
The two factors that determine velocity are....
A: speed and direction
B: direction and distance
C: position and rate
D: distance and mass
please help which one are these . for science class
Answer:
Explanation:
D Distance and Mass
The law of conservation of energy tells us
A. that energy can be transformed from one form to another
B. energy cannot be created or destroyed
C. the total amount of energy will remain the same
D. All of the above
Answer:
it is A
Explanation:
because energy can neither be created nor destroyed - only converted from one form of energy to another.
1 pts
How can two different nonmetals form a compound?
Explanation:
Covalent or molecular compounds form when elements share electrons in a covalent bond to form molecules. Molecular compounds are electrically neutral. Ionic compounds are (usually) formed when a metal reacts with a nonmetal (or a polyatomic ion). Covalent compounds are formed when two nonmetals react with each other.
Nonmetals can form compounds through a process called covalent bonding.
Covalent bonding occurs when two nonmetal atoms share electrons to achieve a stable electron configuration. This sharing of electrons allows both atoms to fill their outermost energy levels or achieve a noble gas electron configuration.
When two nonmetal atoms come together to form a compound, their electronegativities play a crucial role. Electronegativity is the ability of an atom to attract electrons toward itself in a chemical bond. If the electronegativities of the two nonmetals are similar, they will have a similar tendency to attract electrons, resulting in a more equal sharing of electrons.
So, nonmetals can form compounds through covalent bonding by sharing electrons. The extent of electron sharing depends on the electronegativity difference between the nonmetals involved, leading to either polar covalent or ionic bonding.
Therefore, nonmetals can form compounds through a process called covalent bonding.
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Which of the following is true about the speed of light?
A: it is a constant when the light is traveling in a vacuum
B:it speeds up or slows down depending on the observer
C: it’s slowest in a vacuum
D:it varies depending on the color of the light.
Answer:
C. it’s slowest in a vacuum
Explanation:
When light propagates through a material, it travels slower than the vacuum speed, c.
Answer:
A
Explanation:
I took the test
The density of the Earth is greater than the density of an equal volume of water by _____.
5½ times
3½ times
1½ times
7½ times
Answer:
I think the second option is correct
please mark me as brainliest
Help with this review pls!!
Answer:
The 2 forces are a Push and a Pull
Mass is the resistance of change in speed or position when adding force.
Weight is the force of gravity
Tension Force is the pulling force transmitted through a string cable or chain. The formula for this is T = mg + ma.
It gives the particle the same acceleration as all those actual forces together as described by the Newton's second law of motion.
An unbalanced force is when there is 2 forces on opposites of an object both are adding force but one side is stronger than the other.
Friction is a force that heats things up. This happens when we rub our hands together and the heat that is generated from the friction makes our hands warmer.
Static friction is what keeps the box from moving without being pushed, and it must be overcome with a sufficient opposing force before the box will move. Kinetic friction (also referred to as dynamic friction) is the force that resists the relative movement of the surfaces once they're in motion.
List 2 examples of physical properties that don't
change if the sample size changes.
Answer:
Temperature, density
Explanation:
Physical properties of a substance are those properties that do not change the chemical composition of the substance. There are two types of physical properties namely: intensive property and extensive property.
Intensive properties are those physical properties that does not depend on the sample size of the substance involved. Examples of intensive physical properties are temperature, density, boiling point. For example, the size or amount of a substance does not determine the the TEMPERATURE or BOILING POINT of the substance.
HELPPPPP
Jermaine runs exactly 2 laps around a 400 meter track.
Find displacement.
Answer:
0
Explanation:
she runs 2 whole laps around a 400 meter track, but she is always ending up back where she started, therefor there is no displacement.
Is there work being done when kicking a soccer ball?
Answer:
Yes.
Explanation:
There is potential energy in your leg that once comes in contact with the ball turns into kinetic energy.
An Alaskan rescue plane traveling 46 m/s drops a package of emergency rations from a height of 101 m to a stranded party of explorers. The acceleration of gravity is 9.8 m/s^2. Where does the package strike the ground relative to the point directly below where it was released? Answer in units of m.
Answer:
The package strikes 207 m at the ground relative to the point.
Explanation:
Given that,
Speed = 46 m/s
Height = 101 m
Acceleration = 9.8 m/s²
We need to calculate the time
Using equation of motion
[tex]s=ut+\dfrac{1}{2}gt^2[/tex]
Put the value in the equation
[tex]101=0+\dfrac{1}{2}\times9.8\times t^2[/tex]
[tex]t=\sqrt{\dfrac{2\times101}{9.8}}[/tex]
[tex]t=4.5\ sec[/tex]
We need to calculate the distance where the package strikes
Using formula of distance
[tex]x=vt[/tex]
Put the value into the formula
[tex]x=46\times4.5[/tex]
[tex]x=207\ m[/tex]
Hence, The package strikes 207 m at the ground relative to the point.
A model rocket is launched from the ground. It starts from rest and accelerates upward at 15.0 m/s2 for 3.00 s. Disregard gravity. What is the V2? b. Then, it has a downward acceleration of -10.0 m/s2 until it reaches its highest point. What is the highest above the ground that the rocket gets? c. What is the TOTAL time in the air?
Answer:
The final velocity v₂ is 45 m/s
The highest point reached by the rocket is 101.25 m
The total time spent in air by the rocket is 7.5 s
Explanation:
Given;
initial velocity of the rocket, v₁ = 0
final velocity of the rocket, v₂ = ?
upward acceleration of the rocket, a = 15 m/s²
time of acceleration, t = 3 s
The final velocity is given by;
v₂ = v₁ + at
v₂ = 0 + (15 x 3)
v₂ = 45 m/s
The highest point reached by the rocket is given by;
v² = u² + 2ah
where;
u is the initial velocity of rocket when it started decelerating.
thus, u = v₂
v is the final velocity of the rocket at its highest point = 0
0 = v₂² + 2ah
0 = (45)² + (2 x -10 )h
0 = 2025 - 20h
20h = 2025
h = 2025 / 20
h = 101.25 m
Time taken for the rocket to reach its highest point is given by;
h = ut + ¹/₂at²
101.25 = 45t + ¹/₂(-10)t²
101.25 = 45t - 5t²
5t² - 45t + 101.25 = 0
t² - 9t + 20.25 = 0
t = 4.5 s
The total time spent in air by the rocket is given by;
T = upward time + downward time
T = 3 s + 4.5 s
T = 7.5 s
As the cloud passes over the building, a lightning strike occurs and a charge of 0.84C flows through the lightning conductor. The charge flows for 3.5 × 10^-5 s.
Calculate the average current in the lightning conductor during this time. State the formula used in your answer
Answer:
I=24,000 Amp
Explanation:
Electric Current
Is a measure of the quantity of charge Q flowing by a point in a time period of t.
The standard metric unit for the current is the Ampere, often abbreviated as Amps or A.
It can be calculated as:
[tex]\displaystyle I=\frac{Q}{t}[/tex]
The cloud generates a lightning strike that releases a charge Q=0.84 C during a time [tex]t=3.5\cdot 10^{-5}\ sec[/tex].
The current is of course, not of a constant value, but an average value can be calculated by using the above formula:
[tex]\displaystyle I=\frac{0.84}{3.5\cdot 10^{-5}}[/tex]
[tex]\boxed{I=24,000\ Amp}[/tex]
In the heart, what separates the oxygenated and deoxygenated blood?
A. Ventricle
B. Vessel
C.septum
D.atrium
Answer:
C. septum
Explanation:
The septum is the partition separating the right ventricle from the left ventricle. The right ventricle pumps deoxygenated blood to the lungs, and the left ventricle pumps oxygenated blood to the rest of the body.
When walking barefoot, Kevin can walk across the grass easily, but when he crosses the paved street, the street is hot and burns his feet. At the beach he walks quickly across the hot sand to the cool water. Why do some substances feel hot to his feet and others do not? Radiation is heat transfer through waves. Specific heat is the amount of energy required to raise the temperature of a substance 1 degree C.
can someone please help me answer this in the next 15 minutes. ill give a brainiest to whoever can help me. tysm if u do!! :))
Answer: a
Explanation:
Answer: it is a
Explanation: the graph represents the number of speed running and the amount of you add 4 +—0.4 is -0.8! Byee! Plz give me brainliest! Ty! Have a good day!!
please help! newton's laws. please give a legit answer
Answer:
yuhhh
Explanation:
get into it
Both the X- and Y-components of a vector are doubled. Which of the following describes what happens to the resulting Vector?
a) Magnitude increases by √(2
b) Magnitude increases by √(2, and the direction changes
c) Magnitude increases by 2
d) Magnitude increases by 2, and the direction changes
Answer: C. Magnitude increases by 2
Explanation:
If the magnitudes of X and Y vectors are increased, then the resultant vector will increase by a factor of 2 but the direction does not changes. Hence, option c is correct.
What is a vector ?A vector is a physical quantity having both magnitude and direction. For example, force, velocity, work done, momentum, velocity etc. are vector quantities. The quantities which does not have direction are called scalar quantity.
The resultant vector R of vectors in X and Y direction can be written as follows:
[tex]\rm R = \sqrt{x^{2} + y^{2}}[/tex]
If the x and y components are doubled to 2x and 2y then the resultant vector becomes,
[tex]\rm R = \sqrt{(2x)^{2} + (2y)^{2}}\\\\ R = \sqrt{4 (x^{2} + y^{2})\\\\\\ R = 2 \sqrt{x^{2} + y^{2} \\ \\ \\ \\[/tex]= 2R
Therefore, the resultant vector will increases by 2 times. However the direction will not change. Hence, option c is correct.
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How much heat is released by 38 gram sample of water to freeze
A block of wood has a mass of 8 g and occupies a volume of 10 cm3. What is its density?
Answer:
0.8 g/cm³
Explanation:
recall that the definition of density is the mass per unit volume of an object.
or mathematically:
density = mass / volume
here we are given that mass = 8 g and volume = 10 cm³
hence,
density = 8 g / 10cm³ = 0.8 g/cm³
The block has a mass of 8 g with a volume of 10 cm³. It density is mass divided by volume that is 0.8 g/cm³.
What is density?
Density of a substance is the measure of its mass per unit volume. Density is dependent on some other factors beside mass and volume such as bond type, temperature and pressure.
The ratio of density of a substance to the density of water is called its specific gravity. If the substance is denser than water it will sink on water otherwise it will float on it.
The mass of the block of wood = 8 g
volume = 10 cm³
Density = mass / volume
= 8 g/ 10 cm³
= 0.8 g/ cm³
Therefore, the density of the wood block is 0.8 g/ cm³.
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An escaped convict runs 1.70 km due East of the prison. He then runs due North to a friend's house. If the magnitude of the convict's total displacement vector is 2.50 km, what is the direction of his total displacement vector with respect to due East?
Answer:
The right approach will be "47° north of east".
Explanation:
The given values are:
East of prison
= 1.70 km
Displacement vector
= 2.50 km
Now,
The direction will be:
⇒ [tex]Cos \ \theta =\frac{1.7}{2.5}[/tex]
⇒ [tex]=0.68[/tex]
⇒ [tex]\theta=47.16^{\circ}[/tex]
i,e., [tex]\theta = 47^{\circ}[/tex] (north of east)
The direction of his total displacement vector with respect to due East is 1.83km
Resultant vectorGiven the following parameters
Distance ran through east = 1.70km
displacement = 2.50km
Required
Total displacement vector with respect to due north
Using the expression below;
d = √x² + y²
2.5² = 1.7² + y²
y² = 2.5² - 1.7²
y² = 3.36
y = 1.83km
Hence the direction of his total displacement vector with respect to due East is 1.83km
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the energy transferred by a force of a moving object
Answer:
kinetic or mechanical cant remember
Explanation:
Answer:
Hey!!
Kinetic Energy is your answer!
Explanation:
I hope this helped you!
why would it motivate Hollywood to use more realism in special effects?
Answer:
Explanation:
the search for authenticity in films, motivated Hollywood to use more realism in special effects.
You are in a car moving at 50 mph to the right, from the reference frame of the ground. A truck is next to you moving at 30 mph to the right, also from the reference frame of the ground. Which is true from your reference frame of the car?
a. The truck would appear to stand still.This answer is incorrect.
b. The truck would appear to be moving forward.
c. The truck would appear to be moving backward.
PHYSICS HELP PLEASE ONE QUESTION 10 POINTS:)
Case 1 has the greatest strength for the push and pull. Option A is correct.
What is force?The pushes and pulls the body experiences are referred to as force. It can occasionally be used to alter the body's size, shape, and direction.
Mass times acceleration equals force, according to the definition. Newton is its measure.
The force transmitted through a rope, string, or wire as it is tugged by opposing forces is referred to as the tension force.
Energy is drawn equally from both ends by the tension force, which is exerted along the whole length of the wire.
The tension force is acting in the rope causing greater strength for the push and pull.
Hence, option A ia correct.
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If an object is thrown down with force from the top of a building, at a speed of 20.0 m/s, and it hits the ground with
a speed of 40.0 m/s.
I need help ASAP. This is for 15 points
Answer:
Latitude :
runs: east to west
measures : distances north and south of the equator
Longitude :
runs : north to south
measures : the distance east or west of the Prime Meridian
how do you find displacement
Answer:
Displacement can be calculated by measuring the final distance away from a point, and then subtracting the initial distance. Displacement is key when determining velocity (which is also a vector). Velocity = displacement/time whereas speed is distance/time. I hope it helped. Please give brainliest
Explanation:
Rock X is released from rest at the top of a cliff is on earth. A short time later, Rock y is released from rest from the same point as rock X. Both rocks fall for several seconds before landing on the ground directly below the cliff. Frictional forces are considered to be negligible. Which of the following graph correctly shows the vertical velocity of rock X as a function of time? Take the positive direction to the upward.
Answer:
The graph that correctly shows the vertical velocity is B. since the velocity is negative and increases linearly over time
Explanation:
When an object is dropped from rest its movement is ruled only by the effect of gravity.
The acceleration of gravity [tex]g=9.8\ m/s^2[/tex] makes the object gain speed with a linear relation as shown:
vf = g.t
If we take the positive direction to be upward, then the speed will always be negative since the object will go against the positive direction.
Thus, the graph that correctly shows the vertical velocity is B. since the velocity is negative and increases linearly over time
From the given graphs, only the second graph (option B) started from rest (0) and later increased with time.
The given parameters;
Rock XRock yinitial velocity of Rock X = 0The final vertical velocity of the rock X after a short time "t" is calculated as follows;
[tex]v_y_f = v_y_i + gt\\\\v_y_f = 0 + 9.8t[/tex]
The vertical velocity of the rock x will increase with time as it moves downwards.
Therefore, we can conclude that, from the given graphs, only the second graph (option B) started from rest (0) and later increased with time.
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Water is formed when two hydrogen atoms bond to an oxygen atom. The hydrogen and the oxygen in this example are different
They both are two different elements.SO the answer is Element