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
What is the final speed of an object that starts from rest and accelerates uniformly at 3.0 meters per second2 over a distance of 6.0 meters? (1) 8.0 m/s (2) 6 m/s (3) 16 m/s (4) 64 m/s
Answer:
16 m/s sir
Explanation:
because i am in collage
does anyone know the answer ?
Answer:
it is 2 and 3 trust me I gotcha
1) An object is dropped from the top of tower of hight 156.8m and at the same time another object is thrown vertically upward with the velocity of 77.1 m/s from the feetof tower,when and where the object meet
Answer:
The objects meet after 2.033722438s, at a height 136.5334679m from the ground.
Explanation:
Call the object being dropped A and the object being thrown B.
When the objects meet, the time ('t') for both objects will be equal, and the sum of their distances will be equal to 156.8m.
Figure out the distance for A in terms of time, t:
s = ut + (1/2)at²
= 0t +(1/2)(9.8)t²
=4.9t²
Figure out the distance for B in terms of time, t:
s = ut + (1/2)at²
=(77.1)t + (1/2)(-9.8)t²
=77.1t - 4.9t²
We now adding the distances gives us 156.8, so can write:
(4.9t²) + (77.1t - 4.9t²) = 156.8
77.1t = 156.8
∴ t = 2.033722438s
To find the distances, plug in this value for t:
For A: 4.9t² → 20.26653209m
For B: 77.1t - 4.9t² → 136.5334679m
The objects will meet 155.2 meters below the top of the tower after 15.7 seconds.
What is the height?The formula to calculate the time it takes for the object thrown upwards to return to the ground:
Time = 2 * Initial velocity / gravitational acceleration
Plugging in the values given in the question, you can calculate the time as follows:
Time = 2 * 77.1 m/s / 9.8 m/s^2 = 15.7 seconds
To determine when and where the objects meet, you can use the following formula to calculate the height of the object thrown upwards at any given time:
[tex]Height = Initial velocity * time - (1/2) * gravitational acceleration * time^2[/tex]
Plugging in the time calculated above and the initial velocity and gravitational acceleration given in the question, you can calculate the height of the object at the time it returns to the ground as follows:
Height = 77.1 m/s * 15.7 s - (1/2) * 9.8 m/s^2 * (15.7 s)^2 = -1.6 meters
This means that the object thrown upwards returns to the ground 1.6 meters below the point where it was launched. The object dropped from the top of the tower will also have fallen a distance of 156.8 meters in the same amount of time, so the two objects will meet at a point 156.8 meters - 1.6 meters = 155.2 meters below the top of the tower
Learn more about height, here:
https://brainly.com/question/29710719
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What is the relationship between kinetic and potential energy in a roller coaster.
Answer: Kinetic energy is energy that an object has as a result of its motion. Potential energy is stored energy that has not yet been released.
Explanation: All moving objects possess kinetic energy, which is determined by the mass and speed of the object. Potential energy is the energy an object has as a result of its position.
There are screws all around you. Name five examples of screws that you see in everyday life? Think broadly!
Screw pump, Drill Machine, Bottle Caps, Faucets and Car Jack are the five examples of screws that we see in everyday life.
What is screw?Screw is defined as a short, sharp-pointed metal pin with a raised helical thread present round it. It has a slotted head that is used to join things together by rotating it so that it pierces wood and is held tightly on its place. Screw is used in many materials in order to join two frames or bodies with each other. Without this screw, we can't imagine many materials to work together so screw has very high importance.
So we can conclude that Screw pump, Drill Machine, Bottle Caps, Faucets and Car Jack are the five examples of screws that we see in everyday life.
Learn more about screw here: https://brainly.com/question/9620666
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5. Suppose you have three identical drinking cups: one made of plastic, one foam, and one paper.
You want to find out which cup will keep your hot cocoa hot for the longest time.
a. Phrase a formal question for this experiment.
b. What is your hypothesis?
c. What is the experimental variable?
d. What are three important control variables?
e. What type of evidence will you collect to test your hypothesis?
f. Challenge: Conduct your experiment and summarize your findings.
Answer:
a) How the cooling speed changes with glasses of different materials?
b) The glass material influences the cooling rate
c) temperatures initial, final and the time
d) the control variable is time
e)temperature of the beverage heated in a given time
f) best material for insulation was expanded
Explanation:
This is a problem of how to formulate an experiment using the scientific method
a) a question for this problem to follow.
How the cooling speed changes with glasses of different materials?
b) the hypothesis of the experiment is:
The glass material influences the cooling rate
c) we have the independent variable that the experimenter controls
the material of the glass, the initial temperature of the drink and the cooling time
the dependent variable is the one that is measured
the temperature of the drink and the time
d) the control variable is time
e) the evidence would be the temperature of the beverage heated in a given time
f) When conducting the experiment, the thermal conductivity of the material is the most important factor, the one with the lowest thermal conductivity is the one that keeps the drinks longer
in general, the conductivity ends of paper 0.24 W/m K and that of plastic is 0.06 W / m K, of expanded 0.03 W / m K
From these values it is experienced that the best material for insulation was expanded
The U-tube contains a coloured liquid of density 9.6 x102 kg/m3. If the difference in height between the liquid levels in the two arms of the U-tube is 0.16m, calculate the excess pressure (above air pressure) in the cylinder. (Take g = 10 N/kg)
Explanation:
P = ρgh
P = (9.6×10² kg/m³) (10 N/kg) (0.16 m)
P = 1536 Pa
Rounded to two significant figures, the pressure is 1500 Pa, or 1.5 kPa.
I need help on this question
Answer:
the 3rd one im pretty sure
Explanation:
Answer:the answer is answer 3
Explanation:
A person weighing 600N runs up a flight of stairs. It takes the person 10s to get to the top. They are 6m higher at the top of the stairs. How much power was used?
Answer:
[tex]Power = 360W[/tex]
Explanation:
Given
[tex]Force = 600N[/tex]
[tex]Time = 10s[/tex]
[tex]Height = 6m[/tex]
Required
Determine the power used
First, we need to calculate the work done to climb the stairs.
[tex]Word = Force * Distance[/tex]
In this case, the distance represents the height of the stairs.
So:
[tex]Work = 600N * 6m[/tex]
[tex]Work = 3600J[/tex]
Next, we calculate the power using:
[tex]Power = \frac{Work}{Time}[/tex]
Substitute values for Work and Time
[tex]Power = \frac{3600J}{10s}[/tex]
[tex]Power = 360W[/tex]
Hence, the power used by the person is 360 watts
according to Newton's 1st law , an object without a net force ? What
Answer:
an object in motion stays in motion an object at rest stays in rest
Explanation:
A box of mass 60 kg is at rest on a horizontal floor that has a static coefficient of friction of 0.6 and a kinetic coefficient of 0.25
a)The minimum force necessary to start moving the box
b) The friction force and the acceleration of the box if a horizontal force of 400 N is applied
Answer:
a) F = 353.2 N
b) [tex]F_{f} = 147.2 N [/tex]
a = 4.21 m/s²
Explanation:
a) The minimum force necessary to start moving the box s given by:
[tex]\Sigma F = 0[/tex]
[tex] F - \mu_{s}N = 0 [/tex]
[tex] F = \mu_{s}mg [/tex]
Where:
F: is the force applied to move the box
μs: is the static coefficient of friction = 0.6
m: is the mass = 60 kg
g: is the gravity = 9.81 m/s²
[tex] F = 0.6*60 kg*9.81 m/s^{2} = 353.2 N [/tex]
b) The acceleration is:
[tex] F - F_{f} = ma [/tex]
[tex] F - \mu_{k}mg = ma [/tex]
[tex] a = \frac{F - \mu_{k}mg}{m} = \frac{400 N - 0.25*60 kg*9.81 m/s^{2}}{60 kg} = 4.21 m/s^{2} [/tex]
Now, the friction force is:
[tex] F_{f} = \mu_{k}mg = 0.25*60 kg*9.81 m/s^{2} = 147.2 N [/tex]
I hope it helps you!
A 12 kg object speeds up from an initial velocity of 10 m:s-1
north to a final velocity of 15 m.s-north. Calculate the
change in momentum.
Select one:
a. -60 kg.m/s
b. 60 kg.m/s
C. -80 kg.m/s
d. 300 kg.m/s
Momentum = m • v
Original momentum = m • 10 m/s north
Final momentum = m • 15 m/s north
Change = m • (15 - 10) m/s north
Change = m • +5 m/s north
Change = +60 kg-m/s north
what can i do to recycle?
Answer:
You could throw away the following items:
Mixed paper: Newspaper, magazine, junk mail, cardboard, frozen food packaging, wrapping paper, paper bags, etc.
Cans: aluminum, foil, tin, steal, aerosol (empty without pressure) and metal food trays. ...
Unbroken glass: Wine bottles, bottles and jars.
Plastic: Rigid containers like milk jugs, shampoo or water bottles.
Hope this helped
Explain why the focal point of a diverging lens is called a virtual focal point.
f a substance is ionic, then it likely will
Answer:
Many ionic substances will dissolve completely in water to form an aqueous solution of cations and anions; this solution will conduct electricity.
Explanation:
Answer:
Many ionic substances will dissolve completely in water to form an aqueous solution of cations and anions; this solution will conduct electricity.
Explanation:
1. A pumpkin with a mass of 2 kg accelerates 2 m/s/s when an unknown force is applied to it. What is the amount of the force?
Answer:
The answer is 4 NExplanation:
The force acting on an object given it's mass and acceleration can be found by using the formula
force = mass × acceleration
From the question we have
force = 2 × 2
We have the final answer as
4 NHope this helps you
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
A circular track has an inside cirumference of 220m. If the width of track is 3.5m, find its outer circumference.
Answer:
Lc = 242 [m]
Explanation:
The circumference is defined as the circumference length of a circle, this length can be calculated by means of the following equation.
[tex]L_{c}=2*\pi *r[/tex]
where:
Lc = circumference length = 220 [m]
r = radius [m]
Now we can clear r
[tex]r=\frac{L_{c}}{2*\pi } \\\\r = \frac{220}{2*\pi }\\\\r = 35.01 [m][/tex]
Now we can determine the outer radius with the inner diameter plus the width of the track.
R = r + 3.5
R = 35.01 + 3.5 = 38.51 [m]
The outer circumference is:
[tex]L_{c} = 2*\pi *38.51 \\L_{c} = 242 [m][/tex]
Which statement below correctly identifies the difference between LAWS and THEORIES. LAWS describe phenomena (things happening in nature), while THEORIES explain why phenomena exist. Or LAWS are a statement of fact, while THEORIES are a statement of opinion. LAWS are based on facts, while THEORIES are based on "hunches".
Answer: The statement that correctly identified the difference between laws and theories is
(LAWS describe phenomena (things happening in nature), while THEORIES explain why phenomena exist.)
Explanation:
LAW in the field of natural sciences is defined as a statement which describes a remarkable event( things happening in nature) after repeated close observations.
Example of law in natural science includes:
--> law of conservation of mass
--> law of conservation of energy
THEORY in the field of natural sciences is the explanation of these remarkable events after repeated observations. This helps in bringing together facts and hypothesis (ideas that can be tested with further scientific observations).
Example of theory includes:
--> kinetic theory of matter
--> Dalton's atomic theory.
Answer:
in short the answer is b
Explanation:
took nthe test
Length of table is 1.0m,1.00m and 1.000m.Which one is more accurate?
Answer:
1.00 m is a more accurate measured length.
Explanation:
Denote length of the table by L.
For L=1.0 m, there is one significant digit after the decimal.
Care 1: When one more significant digit after decimal considered, the exact number can be from 0.95 to 1.05.
So, the possible span of error [tex]\Delta E_1= 1.05-0.95= 0.1m[/tex]
For L=1.00 m, there is two significant digits after the decimal.
Case 2: When one more significant digit after decimal considered, the exact number can be from 0.095 to 1.005.
So, the possible span of error [tex]\Delta E_2= 1.005-0.095= 0.01m[/tex]
Case 3: For L=1.000 m, there is three significant digits after the decimal.
When one more significant digit after decimal considered, the exact number can be from 0.0095 to 1.0005.
So, the possible span of error [tex]\Delta E_3= 1.0005-0.0095= 0.001m[/tex]
As [tex]\Delta E_1 >\Delta E_2>\Delta E_3[/tex]
So, the least error is in the third case when L=1.00m, hence, L= 1.00m is more accurate.
Why is it important to lean forward and listen
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
Which option is the smallest particle that represents the compound carbon
dioxide?
A. A carbon dioxide molecule B. A carbon dioxide atom
C. A carbon atom and an oxygen atom
D. A carbon ion and an oxygen ion
HELPPPPP
PLEASE I NEED THIS ANSWER FASTTTT
Answer:The answer is A
Explanation: You can instantly eliminate b and d because an ion isn't mentioned, and it is impossible to have a carbon dioxide atom. C is incorrect because there has to be two oxygen's to create a carbon dioxide molecule.
Answer:
D. A carbon dioxide molecule
Explanation:
describe where the information and communication technology can be used it different section?
guys help me i will make you brainliest <3
Answer:
See below
Explanation:
ICT " Information and the communication technology" can be used in sectors like Telecommunications. ADB support for telecommunications and ICT is changing lives across the region. ...
ICT in Education. ICT can improve the efficiency and quality of education at all levels. ...
ICT in Public Sector Management. ...
ICT in Health. ...
ICT in Agriculture and Food Security.
( hope it helped <3 )
Skin cells have the function of protecting the body. What is the function of muscle cells?
Answer:
Skin serves as a protective barrier, a way to sense the world, and a layer that keeps nutrients and water inside the body. Four types of cells make up the skin, and they are produced mainly in the epidermis near the basement membrane. Keratinocytes contain structural keratin and make up the bulk of the epidermis.
Explanation:
Iron filings were sprinkled around these two magnets. What do the iron filings
show?
O A. They show that magnetic field lines point away from the north
pole of magnets.
B. They show the pattern made by the magnetic field lines around the
magnets
C. they show that magnetic field lines often cross over each other when magnets repel
D. they show the locations of the magnetic domains in the magnets
please help no ones questions match mine!!!
Answer:
B. They show the pattern made by the magnetic field lines around the
magnets
Explanation:
Using iron fillings, the pattern of the magnetic field lines around a bar magnet can be known.
Magnetic field lines are the line of force around a bar magnet.
These iron fillings will trace the pattern of the magnetic field around the magnet. The domains of the iron fillings begins to align and orient with that of the prevailing magnetic field around. Those areas with the strongest force will attract more fillings and those far away will attract lesser fillings.Answer:
B
Explanation: E Z
An astronaut is working outside the International Space Station where the atmospheric pressure is essentially zero. The pressure gauge on her air tank reads 690000 Pa. What force does the air inside the tank exert on the flat end of the cylindrical tank, a disk 0.150 m in diameter?
Answer:
Explanation:
Pressure = Force/Area
Given
Pressure = 690,000Pa
Area will be the area of the circular section of the cylindrical tank
Area of a circle =πd²/4
Area of a circle =π(0.15)²/4
Area of a circle = 3.14(0.0225)/4
Area of a circle = 0.07065/4
Area of a circle = 0.0176625m²
Get the force
Force = Pressure * Area
Force = 690,000* 0.0176625
Force = 12,187.125N
Hence the force applied by the air inside the tank is 12,187.125N
1. Day and Night are caused by
10 points
A. The Tilt of the Earth’s Axis.
B. Earth’s Revolution around the sun
C. Earth's ellipical orbit
D. Earth's rotation on its axis.
40 POINTS!
A 2,200 kg SUV is traveling at 25 m/s. What is the magnitude of its momentum?
A. 55,000 kg·m/s
B. 550 kg·m/s
C. 2,200 kg·m/s
D. 88 kg·m/s
Answer:55,000 kg•m/s
Explanation:
Which reaction is an acid-base neutralization reaction?
A. Mg + 2HCl → MgCl2 + H2
B. HCl + NaOH → NaCl2 + H2O
C. SiCl4 → Si2 + 2Cl2
D. N2 + 3H2 → 2NH3
Answer:
option B is correct
Explanation:
neutralization is the reaction between acid and base to produce water and salt therefore option B is correct