Answer:
1.9976 m
Explanation:
An iron bar whose initial length is 2m has its temperature increased from 20 ° C to 120 ° C. What is the final length of the bar? (consider that the coefficient of expansion of iron) is 1.2 x 10-5 1 / ° C (3 points)
Given that,
Initial length of an iron bar, [tex]L_0=2\ m[/tex]
The temperature increased from 20°C to 120°C
The coefficient of expansion of iron is [tex]1.2\times 10^{-5}\ /^{\circ} C[/tex]
We need to find the final length of the bar.
The linear expansion equation is given by :
[tex]\Delta L=\alpha L\Delta T[/tex]
Where [tex]\Delta L[/tex] is the change in length
[tex]\Delta L=1.2\times 10^{-5}\times 2\times (120-20)\\\\=0.0024\ m[/tex]
Also, [tex]\Delta L = L_o-L[/tex]
L is final length
[tex]0.0024= 2-L\\\\L=2-0.0024\\\\=1.9976\ m[/tex]
So, the final length of the bar is 1.9976 m
Carolina (600 N) runs up the stadium (10 meters high) in 9.14 s. How much power did Carolina expend?
i need help!
Which condition of the eye is most likely to be responsible for each of these problems? a: A student who can read the whiteboard from the back of the room but has to strain to read the print in a textbook and gets headaches while reading from a computer screen at home b: A science teacher who has never had eye problems before begins to find it easier to read books and newspapers when they are held further away
Answer:
B Is not a problem
But A is
Explanation:
its either he is long sighted
so he is able to read from far and not near so it's better he sees a doctor to get recommend glasses
A soccer ball is kicked with an initial velocity 13 m/s at an angle of 35 degrees from the horizontal. What is the maximum height reached by the ball?
Answer:
The maximum height reached by the ball is 2.84 m
Explanation:
Given;
initial velocity of the soccer, u = 13 m/s
angle of projection, θ = 35°
The maximum height reached by the ball = ?
Apply the following kinematic equation, to determine the maximum height reached by the ball.
Maximum height (H) is given as;
[tex]H = \frac{U^2sin^2\theta}{2g} \\\\H = \frac{(13)^2(sin \ 35^0)^2}{2*9.8}\\\\H = 2.84 \ m[/tex]
Therefore, the maximum height reached by the ball is 2.84 m
Which statement describes an action-reaction pair?
A. You push against a wall, and the wall applies a force to your
hands.
B. The Sun pulls on the Earth, and the Earth pulls on the Moon.
C. You push a book off the edge of a shelf, and the book falls to the
floor
G
D. You throw a ball straight up, and Earth's gravity pulls it downward.
You push against a wall, and the wall applies a force to your hands. (A)
FOR 45 POINTS PLS ANSWER FAST
1. coefficient of friction
force that opposes a sliding object
2. drag
a force that resists motion
3. friction
friction between a solid and a liquid or gas
4. rolling friction
a force that develops when a mass is accelerated by gravity; stated as Fw = mg
5. sliding or kinetic friction
force that opposes a rolling object
6. starting or static friction
force that opposes the start of motion
7. weight
the ratio of the force necessary to move an object (or keep it moving) and the normal force
Answer:
Other than gravity, the most commonly encountered force is what or the force that resists motion.
friction
the ratio of the force necessary to move an object (or keep it moving) and the normal force
coefficient of friction
friction between a solid and a liquid or gas
drag
a force that resists motion
friction
the force that presses two surfaces together and is directed perpendicular to the contact surface; on a level surface, its magnitude is equal to the force of the object's weight but in the opposite direction
normal force
force that opposes a rolling object
rolling friction
force that opposes a sliding object
sliding or kinetic friction
force that opposes the start of motion
starting or static friction
a force that develops when a mass is accelerated by gravity; stated as Fw = mg
weight
Friction is a force that resists what
motion
It occurs when a surface in motion rubs against another what
surface
What acts parallel to the surfaces that are moving against one another and in the direction opposite to the direction of the motion (represented by F).
Friction
riction is caused by the interaction of the what or what of each object sliding over each other.
atom or molecules
he more contact the atoms are able to make, the greater the what
frictional effect
A what surface will produce more friction (resistance) than a smooth surface
rough surface
The high points on one surface interact with the high points on the other surface allowing atoms and molecules to form temporary what
intermolecular bonds
The more bonds that are allowed to form, the greater the what
friction
he force that opposes the start of motion is referred to as what
starting or static friction
This force is caused by the what that form between two surfaces
tiny bonds
The pull required to keep the block moving at a constant speed in the example above is due to what
sliding or kinetic friction
What occurs as tiny intermolecular bonds are constantly being formed and broken.
Sliding friction
Sliding friction is also affected by the weight of the object and another force called the what
normal force
What is the force of the contact surface pressing opposite the weight of the object, as seen in the diagram below.
normal force
The normal force is always perpendicular to the what
contact surface
The ratio between the sliding friction and the perpendicular normal force is called the what of sliding friction
coefficient
What is represented by the Greek letter mu, μ,
coefficient
he third type of friction that can exist between solid surfaces is what or the force that opposes a rolling object
rolling friction
Friction can also exist between what
solids liquids and gases
Gases and liquids, such as air and water, offer what
resistance to motion
the opposing force between a solid and a liquid or gas
drag
help me plsss, this is worth 30 points!! can someone pls help even if u can only give a few answers it would be helpful.
which event is an example of melting?
Answer:
welding metal
Explanation:
While rowing in a race, John uses his arms to exert a force of 155 N per stroke
while pulling the oar 0.7500 m. How much work does he do in 25 strokes?
Answer:
Workdone = 2906.25J
Explanation:
Given the following data;
Force, F = 155
Distance, d = 0.75
Stroke, s = 25
Mathematically, work done is given by the formula;
Work done = force * distance * stroke
[tex] W = F * d * s[/tex]
Where,
W is the work done
F represents the force acting on a body.
d represents the distance covered by the body.
s is the number of strokes.
Substituting into the equation, we have;
[tex] Workdone = 155*0.75*25[/tex]
Workdone = 2906.25J
HELPPP explain how an electrical circuit works. include the purpose of a battery, voltage, conduction of electrons in a wire, and electron flow direction
Answer:
An electrical circuit is composed of a source of electrical power, two wires that can carry electric current, and a light bulb. One end of both the wires is attached to the terminal of a cell while their free ends are connected to the light bulb. The electrical circuit is broken when the bulb is switched off.
A ball rolling on the ground has what form of energy?
A. KE
B. Chemical
C. PE
D. None
Answer:
a kinetic energy
Explanation:
because it is moving
Mars Odyssey and Mars Express required spectrometric equipment that could analyze Mars's atmosphere and surface composition and temperatures. Using internet resources, describe some home or business technologies that use spectrometric equipment to analyze the atmosphere or temperature.
Answer:
Spectrometric monitoring offers a continuous operating measurement system for nuclide specific detection of low level gamma contamination in air and in liquids. A spectroscopic analysis is performed in order to identify radionuclides.
Explanation:
i think
Answer:
If you need to match paint for a repair, you can take a paint chip to a hardware store, and they can analyze it to mix paint for an exact match to the chip.
Light bulb manufacturers probably use spectrographic analysis to create bulbs that are rated warm, cool, etc.
Manufacturers of sunglasses probably analyze the intensity of light at different frequencies (colors) that are transmitted by the glasses.
Steel makers can measure the temperature of molten metal in a furnace using a radiometer.
7. In what ways has science harmed us?
Answer: At several different levels, scientific awareness will enhance the quality of life, from the routine functioning of our daily lives to global issues. In energy, conservation, agriculture, health, transportation, communication, security, economics, recreation, and discovery, science informs public policy and personal decisions.
Explanation:
Hope This Helps! : )
2. What was the main purpose of Title IX?
Answer:
Title IX of the Education Amendments Act of 1972 is a federal law that states: "No person in the United States shall, on the basis of sex, be excluded from participation in, be denied the benefits of, or be subjected to discrimination under any education program or activity receiving Federal financial assistance."
Explanation:
3. The soccer kicker kicks a 2 kg football with a force of 68 N. How fast will the ball accelerate down the field?
m = _______
a = ________
Fnet = _____
Answer:
[tex]\boxed {\boxed {\sf m= 2 \ kg , \\a= 34 \ m/s^2, \\\F= 68 \ N}}[/tex]
Explanation:
The formula for force is:
[tex]F=m*a[/tex]
If we rearrange the formula to solve for a (acceleration), the formula becomes
[tex]\frac{F}{m} =a[/tex]
The force is 68 Newtons. Let's convert the units to make the problem easier later on. 1 N is equal to 1 kg*m/s², so the force of 68 N is equal to 68 kg*m/s².
The mass is 2 kilograms.
[tex]F=68 \ kg*m/s^2 \\m= 2\ kg[/tex]
Substitute the values into the formula.
[tex]\frac{68 \ kg*m/s^2}{2 \ kg} =a[/tex]
Divide. Note that the kilograms will cancel each other out (hence why we changed the units).
[tex]\frac{68 \ m/s^2}{2}=a[/tex]
[tex]34 \ m/s^2=a[/tex]
The acceleration is 34 meters per second squared.
Why does the lens need to be thicker for viewing nearby objects?
Answer: To focus on a near object – the lens becomes thicker, this allows the light rays to refract (bend) more strongly. To focus on a distant object – the lens is pulled thin, this allows the light rays to refract slightly.
Explanation:
Please can you solve it?How to find the complete displacement of a body in this case:
calculating the area under the graph by dividing it
into a triangles and rectangles
A2 = 0.5 × h × b
= 0.5 × 10 × 5 = 25
A1 = 0.5 × 10 × 15 = 75
A4 = 0.5 × 15 × 10 = 75
A4 = h × b = 10 × 35 = 350
total displacement = 25 + 75 + 75 + 350 = 525
What force acts on an object in free fall?
Answer:
gravitational force. in my view but m not sure
How do the individual forces compare when the rider experiences a sensation being lighter than his normal weight ? What is the acceleration direction when this occurs ?
Answer:
When the elevator is accelerating downward, the person feels lighter due to the downward normal force being less than the person's weight.
Explanation:
A person riding in an elevator subjected to a series of unbalanced forces depending on the direction the elevator is travelling.
Two forces are acting on the person; the force of gravity and the upward normal force from the elevator.
When the elevator is going upwards with acceleration a, the person feels heavier than his normal weight, due to the upward normal force being greater than the person's weight. N = mg + ma
When the elevator is moving downwards with acceleration a, the person feels lighter due to the downward normal force being less than the person's weight. N = mg - ma
However, when the elevator is moving up or down at constant velocity ie. acceleration a = 0, the person experience a normal force equal to weight. N = mg
When the elevator is moving downwards with acceleration a = g, the person experiences weightlessness. N = (mg - mg) = 0
Al inicio de un paseo recorrerá una distancia de 200 km/h, los primeros 120 km lo hará a una velocidad constante de 60 km/h y el resto a una velocidad constante de 90 km/h,¿Cuánto tiempo en horas total durará el viaje?
Responder:
1 hora 20 min
Explicación:
Paso uno:
datos dados
Durante los primeros 120 km, se nos dice que la velocidad es de 60 km / h.
sabemos que velocidad = distancia / tiempo
por lo tanto, distancia = velocidad * tiempo
deja que el tiempo sea ty la velocidad sea s
distancia = s * t
distancia = 60t -------------------- 1
Segundo paso:
Durante los segundos 80 km, se nos dice que la velocidad es de 90 km / h.
sabemos que velocidad = distancia / tiempo
por lo tanto, distancia = velocidad * tiempo
deja que el tiempo sea ty la velocidad sea s
distancia = s * t
desatancia = 90t ------------------- 2
La distancia total recorrida es de 200 km.
entonces 200 = 60t + 90t
200 = 150t
t = 200/150
t = 1,3 horas
Por lo tanto, el viaje tendrá una duración de 1 hora y 20 minutos aproximadamente.
How is a metre related to kilometre?
Answer:
The kilometer is unit of length in the metric system equivalent to one thousand meters. 1Km is equivalent to 0.6214 miles.
Explanation:
Length is the measurement of the distance from the initial point to the final point.
________________________________________________________
SI Unit:The Si unit of length is meter, that means length is measured in meter units.
____________________________________Relation:The Relation between meter and kilometer is that they both are the units of the length, also the Kilometer(Km) is equals to the 1000 meters(m).
1Km = 1000 meter
1m = 0.001 Km
____________________________________Best Regards,'Borz'Predict If you sit on a moving bus and toss a coin straight up into the air, where will it land?
Answer:
the same place you threw it from
Explanation
static electricity 5 examples and current electricity 5 examples
Explanation:
static electricity
1.lighting
2.rub your shoe on the carpet
3.walking across a carpet
4.touching a metal door handle
5. pulling your hat off and having your hair stand on end.
current electricity
1. Lightning.
2. Batteries.
3. charging your phone
4. hair dryer
5. microwave food
Determine the magnitude of the force for each direction. A. Add the forces that are applied in the same direction. B. Subtract forces applied in the opposite direction
Answer:
A) R = F1 + F2
B) R = | F1 - F2 |
Explanation:
A) For forces acting in the same direction
we will add up the forces : lets assume the forces to be F1 , F2
Then the magnitude of the forces acting in the same direction will be
R = F1 + F2
B) For forces acting in the opposite direction
we will subtract the forces i.e. stronger force - weaker force . assuming the forces to be F1 , F2
Hence the magnitude of the resultant force = R = | F1 - F2 |
A fighter jet flies 3 km west and then 2 km east in 8 minutes. Determine the jet's average velocity. (Remember to convert!)
Answer:
7.69km/hr due east
Explanation:
Given parameters:
Displacement due west = 3km
Displacement due east = 2km
Time taken = 8 minutes
Unknown:
Average velocity = ?
Solution:
Average velocity is the rate of change of displacement with time.
Velocity = [tex]\frac{displacement}{time }[/tex]
Displacement is deals with the start and the end;
Here, displacement = 3km - 2km = 1km due east
Time = 8min
60min = 1hr
8min = [tex]\frac{8}{60}[/tex] = 0.13hr
Average velocity = [tex]\frac{1km}{0.13hr}[/tex] = 7.69km/hr due east
Using a force of 10 N, you
push a shopping cart 10 m.
How much work did
you
do?
Answer:
100 JExplanation:
The work done by an object can be found by using the formula
workdone = force × distance
From the question we have
workdone = 10 × 10
We have the final answer as
100 JHope this helps you
HELP PLZ IM BEING TIMED!!
What is the vertical acceleration of a dart that is launched horizontally with an initial velocity of 2.3 m/s?
-9.8 m/s
2 0 m/s2
2.3 m/s2
9.8 m/s2
Answer:
-9.8
Explanation:
EDGE 2021
The vertical acceleration of a dart is equal to the negative of acceleration due to gravity (- g). The vertical acceleration of the dart is equal to -9.8m/s². Therefore, option (1) is correct.
What is the acceleration due to gravity?Acceleration due to gravity is the acceleration acquired by a body due to gravitational force. As gravity has both magnitude and direction, so it is a vector quantity. Acceleration due to gravity is expressed by the symbol 'g'. The SI unit of g is m/s² and the value of g (acceleration due to gravity) on the surface of the earth is 9.8 m/s².
Let us suppose a body with mass (m) is dropped from a height ‘h’ above the surface of the earth with mass (M), it starts to move downwards with an increase in velocity to the earth's surface.
The body starts to accelerate toward the earth’s center under the action of gravitational force which is at a distance ‘r’.
Then, ma = GMm/r²
a = GM/r²
Therefore, the value of the acceleration due to gravity (g) = GM/r2.
Any object freely falling to the surface of the earth has acceleration due to gravity is 9.8m/s².
If the object moves away from the surface of the earth then it experiences the gravitational pull of the earth. Therefore, the acceleration of dart vertically is equal to -g.
Therefore, the vertical acceleration of the dart is equal to -9.8m/s².
Learn more about acceleration due to gravity, here:
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how does the electric current of an AC generator differ from that of a DC generator ?
A- it flows through the permanent magnets
B- it is much stronger
C- it is much weaker
D- it constantly reverses direction
The difference between the AC and the DC is that the AC current is always reversing. Option D
What is a generator?We have to know that the term generator has to do with a device that can be used in the production of electricity. The principle upon which the generator works is the principle of the electromagnetic induction.
Now we know that when we have a DC generator, the current that it is able to supply can be found to be constant but in the case of the AC generator, there is a constant change since the direction is reversing.
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The electric current of an AC generator differs from that of a DC generator in that it constantly reverses direction.
The correct option is D.
What are AC and DC generators?A mechanical device known as an AC generator transforms mechanical energy into AC or alternating current electrical power. Periodically, the electrical current in an AC generator changes direction.
A mechanical device known as a DC generator transforms mechanical energy into DC or direct current electrical power. The electrical current in a DC generator flows in one direction.
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A rock is thrown upwards at 13.5 m/s. How long does it take to fall back to the ground?
The si unit of average speed is m.s. True or False. anyone who is right I will give him brainlist if you are sure
True
Explanation:
Average speed is a scalar magnitude as opposed to average velocity which is a vector. The unit of measurement in the International System (S.I.) of the average speed is the meter per second (m/s).
what is measurement
Answer:
the size, length, or amount of something, as established by measuring.
Explanation: