Answer:
B. a piece of paper being torn
Explanation:
A chemical change is one that cannot be reversed. This means the original properties of the substance or object cannot be restored.
If you cook a raw egg, it would turn into a boiled egg (or a poached egg, however it is being cooked). The reaction is irreversible, so you cannot turn the cooked egg back into a raw egg - it is basically impossible to 'uncook' an already cooked egg.
When you toast a piece of bread, it turns into toast. You can't 'untoast' it back into bread. The chemical changes have already occurred and cannot be undone.
If you tear a piece of paper, it is still paper. You are only ripping it, not changing anything about it. You could simply tape the torn bit back to the original bit, or glue it - either way, it is still paper and nothing has occurred to drastically change the physical state of it.
Therefore, B is not a chemical change.
The half-life of carbon-14 is 5370 years. The carbon-14 levels in a fossil indicate that 6 half-lives have passed. How old is the fossil?
75,200 years
35,000 years
32,220 years
50,000 years
Answer:
32200
6*5370
Explanation:
Flag In reaching her destination, a backpacker walks with an average velocity of 1.34 m/s, due west. This average velocity results because she hikes for 6.44 km with an average velocity of 2.68 m/s, due west, urns around, and hikes with an average velocity of 0.447 m/s, due east. (a) How far east did she walk? (b) If she did not turn around and walked due east, how many hours would it take her to reach her destination with an average velocity of 1.34m/s due west?
Answer:
[tex]s_2=-806m[/tex]
Explanation:
From the question we are told that
Velocity 1 [tex]v=1.34m/s \angle west[/tex]
Distance [tex]d=6.44km=>6440m[/tex]
Velocity 2 [tex]v_3=2.68m/s[/tex]
Velocity 3 [tex]v_3=0.447m/s \angle east[/tex]
Generally the equation for VT is mathematically given by
[tex]VT=v_1t_1 +V_2t_2[/tex]
[tex]VT=2.68(2400)-0.447t_2[/tex]
[tex]1.34t_1+1.34t_2=2.68(2400)-0.447t_2[/tex]
[tex]t_2=1804s[/tex]
Therefore
[tex]s_2=v_2t_2=(-0.447)(1804)[/tex]
[tex]s_2=-806m[/tex]
What is the weight of an object on Earth with a mass of 90.0kg?
Answer:
Weight (Force) = mass x acceleration due to gravity Weight = 90.0 kg x 9.80 m/s2 Weight = 882 N or 882 kg m/s2 Page 2 Newton's Notes 2 Gravity has an effect on an object in the vertical direction only.
Answer:
882.9N
Explanation:
1kg is 9.81n
During the course of a trajectory, is the vertical component of the velocity a constant or a changing value? ___________________ If it is a changing value, then describe its changes (increasing, decreasing, or ...)
Answer:
1) Changing value
2) The velocity is decreasing for upward motion and increasing for downward motion due to gravitational force
Explanation:
1) A trajectory is the motion of an object which is being acted upon by specified forces. The flight path of an object in projectile motion is its trajectory
During the course of a trajectory, the vertical component of the velocity, [tex]v_y[/tex], is a changing value
2) The vertical component of the velocity first decreases, during the upward motion, according to the following equation;
[tex]v_y[/tex] = [tex]u_y[/tex] - g·t
Where;
[tex]v_y[/tex] = The vertical component of the velocity after a given time, t
[tex]u_y[/tex] = The initial vertical velocity
t = The time of motion of the trajectory
g = The acceleration due to gravity ≈ 9.8 m/s²
When the vertical velocity of the object decreases to zero, which is the point at which the object reaches the maximum height of its motion, the direction of the vertical motion of the object reverses, and object begins to accelerate and increase its velocity downwards according to the following equation;
[tex]v_y[/tex] = [tex]u_y[/tex] + g·t
Therefore, the velocity of the object is decreasing on its way up, and then increasing on its way down.
Is it possible to have acceleration at constant velocity
Answer:
No
Explanation:
It is not possible to have acceleration at constant velocity
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The girl is pulling the wagon at an angle of 36.9 degrees. She is pulling with a force of 50N and the boy is pushing with a force of 30N. The mass of the wagon and books together is 90 KG. Determine the force of gravity and the normal force acting on the wagon and books.
Answer:
below
Explanation:
1.1115 im not sure tho
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Answer:
The answer is the They are equal and act in the oppisite directions
Explanation:
4. What will happen to the amount of kinetic energy if an object's mass
decreases?
A. The kinetic energy will increase I
B. The kinetic energy will decrease
C. The kinetic energy will remain constant
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Answer:
D I think
Explanation:
Im just guessing dont trust 100%
A pencil aapears bent when dippes partially in a beaker contaning water why?
i
the pencil appears to be bent when dipped in water because the reflected light ray from the immersed part of the pencil refracts when travels from water to air. however, it appears to be bent because our eyes expect light to travel in straight line
1) Li + ČI>LICI
How many atoms are in this?
Answer:
2 atoms
Explanation:
Plants make ___________ using carbon dioxide, water and energy from the sun.
a Minerals
b Vitamins
c Carbohydrates
dFats
Answer:
I think it's carbohydrates
Explanation:
The energy from light causes a chemical reaction that breaks down the molecules of carbon dioxide and water and reorganizes them to make the sugar (glucose) and oxygen gas.
which forces are contact forces give one example of each
Answer:
A contact force is any force that requires contact to occur. Contact forces are ubiquitous and are responsible for most visible interactions between macroscopic collections of matter. Pushing a car up a hill or kicking a ball across a room are some of the everyday examples where contact forces are at work.
two 100 kg astronauts are floating in space. the first astronaut is moving at 5 m/s while the second is at rest. the two astronauts collide. both astronauts are moving at 3 m/s. based on the information provided, which of the following statements is true?
Answer:
The true statement is;
Neither momentum or kinetic energy is conserved
Explanation:
The question relates to the verification of the conservation of linear momentum, and kinetic energy
The given parameters are;
The mass of each astronaut = 100 kg
From which, we have;
The mass of the moving astronaut, m₁ = 100 kg
The mass of the stationary astronaut, m₂ = 100 kg
The initial velocity of the moving astronaut, v₁ = 5 m/s
The initial velocity of the stationary astronaut, v₂ = 0 m/s
The final velocity of both astronauts, v₃ = 3 m/s
The sum of the initial momentum of both astronauts is given as follows;
[tex]P_{initial}[/tex] = m₁·v₁ + m₂·v₂ = 100 kg × 5 m/s + 100 kg × 0 m/s = 500 kg·m/s
[tex]P_{initial}[/tex] = 500 kg·m/s
The sum of the final momentum of the astronauts is given as follows;
[tex]P_{final}[/tex] = m₁·v₃ + m₂·v₃ = (m₁ + m₂) × v₃ = (100 kg + 100 kg) × 3 m/s = 600 kg·m/s
[tex]P_{final}[/tex] = 600 kg·m/s
∴ [tex]P_{initial}[/tex] = 500 kg·m/s ≠ [tex]P_{final}[/tex] = 600 kg·m/s
[tex]P_{initial}[/tex] < [tex]P_{final}[/tex], therefore, the sum of the linear momentum of both astronauts is not conserved
The sum of the initial kinetic energy of each astronaut is given as follows;
[tex]K.E._{initial}[/tex] = 1/2·m₁·v₁² + 1/2·m₂·v₂² = 1/2 × 100 kg × (5 m/s)² + 1/2 × 100 kg × (0 m/s)² = 1250 Joules
[tex]K.E._{initial}[/tex] = 1250 Joules
The sum of the final kinetic energy of the astronaut is given as follows;
[tex]K.E._{final}[/tex] = 1/2·m₁·v₃² + 1/2·m₂·v₃² = 1/2 × 100 kg × (3 m/s)² + 1/2 × 100 kg × (3 m/s)² = 900 joules
[tex]K.E._{final}[/tex] = 900 joules
[tex]K.E._{initial}[/tex] > [tex]K.E._{final}[/tex], therefore, the kinetic energy is not conserved
From which we get that neither momentum or kinetic energy is conserved.
What is the molar mass of Sodium Hydroxide, NaOH?
Answer:
40g/mol
Explanation:
The molar mass of a compound is the mass in grams of one mole of the substance.
To find the molar mass of NaOH;
a. Atomic mass of Na = 23g
O = 16g
H = 1g
b. So, the NaOH will have a molar mass of:
23g + 16g + 1g = 40g/mol
The molar mass of NaOH is 40g/mol
If an 80 kg swimmer pushes off a pool wall with a force of 250 N, what is her
acceleration?
Answer:
Explanation:
Force = Mass*Acceleration
Remember this formula because its one of the most used formula in all of physics.
250N = 80kg*Acceleration
a = 3.125 m/s^2
There would definitely be friction because of the water, but since this says high school physics, you prolly can assume it to be negligible
A rocket has a mass of 80,000 kg and accelerates at a rate of 35 m/s2. Calculate the force that provides this acceleration,
Explanation:
Given
Mass(M) = 80,000 kg
Acceleration (a) = 35 m/s²
Force (F) = ?
We know we have the formula
F = m * a
= 80000 * 35
= 2800000
= 2.8 * 10 ^ 6 N
The force is 2.8 * 10 ^ 6 N.
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If a rocket has a mass of 80,000 kg and accelerates at a rate of 35 m/s2. then the force that provides this acceleration would be 2800000 Newtons.
What is Newton's second law?Newton's Second Law states that The resultant force acting on an object is proportional to the rate of change of momentum.
The mathematical expression for Newton's second law is as follows,
F = m*a
As given in the problem we have to find the force that provides the acceleration of 35 meters / second², if the rocket has a mass of 80,000 kg,
The force acting on the rocket = 80,000 × 35
= 2800000 Newtons
Thus, the force acting on the rocket would be 2800000 Newtons.
To learn more about Newton's second law here, refer to the link;
brainly.com/question/13447525
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The paths of the alpha particles depend on the forces on them in the metal.
Describe the model of the atom which is used to explain the paths of alpha particles aimed at thin sheets of metal foil.
Answer:
During the experiment, alpha particles bombarded a thin piece of gold foil. The alpha particles were expected to pass easily through the gold foil. ... The discovery of the nucleus was a result of Rutherford's observation that a small percentage of the positively charged particles bombarding the metal's surface...
Explanation:
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Rutherford's model of atoms describes the atom as a tiny, dense particle which contains a positively charged nucleus with electrons which are negative charged moving in orbitals.
What is Rutherford's model?Rutherford's model of atoms described the atom as a tiny, dense, positively charged core particle which is called a nucleus, in which nearly all the mass of the atom is concentrated, around within the nucleus which the light, negative constituents, called electrons, circulate at some specific distance, much like the planets which are revolving around the Sun.
During the Rutherford's experiment, the alpha particles are bombarded on the thin piece of gold foil. The alpha particles were expected to pass easily through this gold foil. The discovery of the nucleus of atom was a result of the Rutherford's observation in which a small percentage of the positively charged particles that is protons bombarding on the metal's surface.
Learn more about Rutherford's model here:
https://brainly.com/question/11749615
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On the way home from school, you notice the speedometer on the car is at 5,200 miles. When you get home, the speedometer reads 5,208 miles. With only this information what value could you calculate?
O Velocity
O Displacement
O Acceleration
O Distance
Answer:
O Distance
Explanation:
With the given information, it is possible to find the distance of the car has traveled on the home from school.
This is possible because distance is the length of path a body covers.
From the given values:
Distance = 5208 - 5200 = 8miles
It is not possible to find the displacement because no direction was given.
Also velocity is not possible since the time frame of travel was not state.
How is electric charge different than gravity? A. Electric charge has a smaller constant B. Gravitational force can only be positive C. Charges can be either positive or negative for electric charge D. The calculation of the radius is different
B and C are both true statements.
Why can't a distance/time graph be used to find an object's velocity?
Answer:
for velocity we have to use displacement &distance is for speed
A car accelerates from 20.0 m/s to 28.0 m/s over a distance of 50.0 m. What is the car’s acceleration?
Answer:
Explanation:
[tex]V^2=V^2_o+2a(x_f-x_i)[/tex]
[tex]28^2=20^2+2a(50)\\784=400+100a\\384=100a\\a=3.84m/s^2[/tex]
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????????????????what’s the answer
Answer:
I don't know what do u. mean
Describe the relationship between frequency and wavelength.
Answer:
frequency is equal to the wavelength multiply by the speed of light
Explanation:
wavelength multiply by the speed of light Will give you the frequency
Which is the main purpose of an experimental conclusion?
O A. to describe the steps in an experiment
O B. to state whether a hypothesis has or has not been
supported
O C. to criticize the observations that led to the investigation
O D. to explain how data was collected
Answer:
the Answer is B
because the purpose of experimental conclusion it is to prove rather is a right or wrong is a hypothesis is right or wrong
When electricity moves through a metal wire, the wire is
A. A resistor
B. A conductor
C. an insulator
D. a power supply
When electricity moves through a metal wire, the wire is option B. A conductor.
What is a Conductor?Conductors are materials that allow electricity to flow easily through them. An electric current flows when electrons move through a conductor, such as a metal wire. The moving electrons can collide with the ions in the metal. This makes it more difficult for the current to flow and causes resistance.The flow of electricity through a wire is the flow of electrons. An electron is a negatively charged subatomic particle. In electrical conductors, the flow of electricity results from the movement of electrons from one atom to the next.To learn more about conductors, refer to: https://brainly.com/question/27533161
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PLEASE PLEASE
HELP!!!!!!!!
Answer:
b 8W
Explanation:
i dont know u find out
Answer:
B. 8 I believe that this is the answer
Which of the following best describes what displacement is?
o displacement is a vector, it must have magnitude only
o displacement is a scalar, it must have magnitude and direction
o displacement is a scalar, it must have magnitude only
o displacement is a vector, it must have magnitude and direction
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What is the second daughter element from the nuclear fission reaction shown below? (solve
for x) *
(3 Points)
Answer:Cs
Explanation: for this one 92-37 is 55
