why is science always changing
Answer:
Science is changing because little by little scientists descover new things.
Explanation:
Discovery
Hope this helps:)
What did Thomson’s and Rutherford’s experiments have in common? They both used charged particles in their experiments. They both used emission spectra to discover electron clouds. They both compared the atom to an indivisible sphere. They both discovered electron clouds.
Answer:
Both Thomson and Rutherford used charged particles in their experiments.
Explanation:
two trucks leave at different times (from the same place) headed for the same city. Both trucks arrive at the same time. Based on the this information, which of the following statements is true? A. The trucks traveled the same distance in the same amount of time B. The trucks were traveling at the same average speed C. The trucks traveled different distances D. The truck that left later traveled faster
the particles in a gaseous substance can move easily because the____
a. particles are free to move
b. containing vessel is to big
c. force between them is weak
d. particles are moving with great speed
Answer:
a option okkkkkkkkkkkkkk
Answer:
particles are free to move
Both acids and bases produce ions when dissolved in water. Propose a way to describe what
hydroxide ions (OH-) and H+ (hydrogen) ions are. What do they have to do with acids and
bases and the pH scale?
Answer:
See explanation
Explanation:
Acids and bases contain ions that interact with water. According to the Arrhenius definition, acids are substances that produce hydrogen ion in water while bases are substances that produce hydroxide ion in water.
The pH scale is a graphic description of the hydrogen or hydroxide ion present in a sample. Since pH= -log[H^+], the higher the pH , the lower the hydrogen ion concentration and vice versa.
Similarly, pOH= -log [OH^-] , hence the more the OH^- concentration the lower the pOH.
However pH + pOH =14.
Thus the concentration of hydrogen or hydroxide ions present determines the pH of any solution.
If you took a 20 g rock from the Earth to the moon, which would change?
a. volume
b. mass
c. weight
d. density
Answer:
weight of tock would change
In the diagram, q1 = -6.39*10^-9 C and q2 = +3.22*10^-9 C. What is the electric field at point P? pls help
Answer:
Below
Explanation:
First draw the vectors that represent both electric fields.
E1 is the elictric field created by q1, E2 is the one created by q2.
● q1 is negative so E1 will point from P.
● q2 is positive so E2 will point out of P
(Picture below)
■■■■■■■■■■■■■■■■■■■■■■■■■■
The resulting electric field is equal to the sum of the two fields since both vectors are colinear.
Let E be the total field.
● E = E1 + E2
The formula of the electric field intensity is:
● E = K ×(q/d^2)
-K is Coulomb's constant
-d is the distance between the charge and the object ( here P)
-q is the charge
■■■■■■■■■■■■■■■■■■■■■■■■■■
● E1 = K × (q1/d1^2)
The distance between q1 and P is the qum of 0.15 m 0.25 m. (0.4 m)
Coulombs constant is 9×10^9 m^2/C^2
● E1 = 9×10^9 ×[-6.39 × 10^(-9)/ 0.4^2]
● E1 = -359.43 N/C
■■■■■■■■■■■■■■■■■■■■■■■■■■
● E2 = K ×(q2/d^2)
The distance between q2 and P is 0.25 m.
● E2 = 9×10^9×[3.22×10^(-9) /0.25^2]
● E2 = 463.68 N/C
■■■■■■■■■■■■■■■■■■■■■■■■■■
● E = E1 + E2
● E = -359.43+463.68
● E = 105.25 N/C
At what distance from the centre of the earth its acceleration due to gravity becomes one third only? [Mass and radius of earth = 6x10 24 kg & 6.4x10 6 m resp.]
Answer:
235
Explanation:
Based on what you know about how light travels, explain why
you can't see the back of your own head without using a mirror,
camera or other device.
How many liters in 1 milliliter ??? HELP PLZ
A cylinder is submerged in water as illustrated in the diagram. At which two positions is the pressure the same?
1- A and B
2- B and C
3- A and D
4- B and D
Answer:
it is two or three
Explanation:
Answer:
2- B and C
Explanation:
The arrows are at the same location in opposite ends and are the same length.
A ladder rests in limiting equilibrium against a rough vertical wall and with its foot on rough horizontal ground, the coefficient of friction at both points of contact being 0.5. The ladder is uniform and weighs 300N. Find the angle which the ladder makes with the horizontal ground. Find also the normal reactions at the wall and the ground.
Answer:
θ = 36.9°
N = 240 N
R = 120 N
Explanation:
Draw a free body diagram. There are five forces on the ladder:
Weight force mg pulling down at the center of the ladder,
Normal force N pushing up at the ground,
Friction force Nμ pushing right at the ground,
Reaction force R pushing left at the wall,
and friction force Rμ pushing up at the wall.
Sum of forces in the x direction:
∑F = ma
Nμ − R = 0
R = Nμ
Sum of forces in the y direction:
∑F = ma
N + Rμ − mg = 0
N + Nμ² − mg = 0
N (1 + μ²) = mg
1 + μ² = mg / N
Sum of torques about the base of the ladder.
∑τ = Iα
mg (L/2 cos θ) − R (L sin θ) − Rμ (L cos θ) = 0
mg (L/2 cos θ) = R (L sin θ) + Rμ (L cos θ)
mg (1/2 cos θ) = R (sin θ + μ cos θ)
mg / 2 = R (tan θ + μ)
mg / (2R) = tan θ + μ
Substitute:
mg / (2Nμ) = tan θ + μ
(1 + μ²) / (2μ) = tan θ + μ
(1 − μ²) / (2μ) = tan θ
Given μ = 0.5:
tan θ = (1 − 0.5²) / (2 × 0.5)
tan θ = 0.75
θ = 36.9°
The reaction forces are:
N = mg / (1 + μ²) = 240 N
R = Nμ = 120 N
To measure the amount of mass in an object, which piece of equipment would be used?
a. balance
c. graduated cylinder
b. Newton spring scale
d. meter stick
When looking at the effect of PH on sucrase activity, what was the wavelength of light used in the spectrophotometer?
Answer:
540 nm
Explanation:
Sucrase is a digestive enzyme. It is the catalyst in the hydrolysis of sucrose into the two subunits that it is made up of namely; fructose and glucose.
Enzymes are known to function best at optimum pH. As the pH of sucrase departs from its ideal pH, its activity decreases.
The activity of sucrose is studied using a spectrophotometer of wavelength about 540nm.
What does a mechanical wave do with its energy?
Answer: A mechanical wave is a wave that is an oscillation of matter, and therefore transfers energy through a medium. While waves can move over long distances, the movement of the medium of transmission the material is limited. Therefore, the oscillating material does not move far from its initial equilibrium position. Mechanical waves transport energy.
Explanation:
Which of the following is part of the internal energy of a substance?
O A. Kinetic energy from nuclear forces
B. Kinetic energy from intermolecular forces
O C. Potential energy from nuclear forces
O D. Potential energy from intermolecular forces
The correct answer is Potential energy from intermolecular forces.
Potential energy from intermolecular forces is part of the internal energy of a substance, therefore the correct option is D.
What is internal energy?It is the total energy of the substance that is contained in the system which is the sum of all the kinetic energy and potential energy of the molecules and the atoms contained in it.
The potential energy of the intermolecular forces is also part of the internal energy of the substance.
Learn more about internal energy
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Which of the following could be used to convert chemical energy to heat energy?
a. a chair sitting still
c. a leaf absorbing sunlight
b. a battery powering a flashlight d. a rock hitting the ground
Answer:
C
Explanation:
Inside a battery there are chemical reactions. When the battery is powering a flashlight, this chemical energy gives a heat one.
QUESTION 3
According to Freud, moral standards are developed as a result of:
a. identification
b. id control
C. ego control
d. defense mechanisms
Answer:
it is for ego control and for super ego control
here's some more information:
Standards provide people and organizations with a basis for mutual understanding, and are used as tools to facilitate communication, measurement, commerce and manufacturing. Standards are everywhere and play an important role in the economy, by: facilitating business interaction.
What percent of the gross domestic product (GDP) is currently generated by the service industry?
68 percent
71 percent
82 percent
95 percent
The global economy is heavily reliant on the service sector, which accounts for more than two-thirds of global GDP, over three-quarters of foreign direct investment in advanced nations, the majority of worker employment, and the majority of job growth. Thus, option B is correct.
What GDP is generated by the service industry?The service sector, often known as the tertiary sector, makes up the third tier of the three-sector economy. Instead of creating products, this sector provides training, consulting, and maintenance and repairs.
The GDP of the nation is significantly impacted by the service sector. Through trade in services, it not only generates many jobs, but also significantly improves the country's economic performance.
Therefore, 70% of GDP is made up of consumer expenditure. The retail and service sectors are important to the American economy.
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A container contains 200g of water at initial temperature of 30°C. An iron nail of mass 200g at temperature of 50°C is immersed in the water. What is the final water temperature? State the assumptions you need to make in your calculations.
[Given the value of specific heat capacity of water is 4200 J kg^-1 °C^-1 and that of iron is
450 J kg^-1 °C^-1]
Answer:
Assuming there is no heat loss to the surrounding.
Heat lost by iron equals heat gained by water.
0.2(450)(50-x)=0.2(4200)(x-30)
x=31.94 °C
Explanation:
3. There are twice as many people in the household, but your income has also doubled. Is your new
tax liability about twice as much as when you were single, more than twice as much, or less than
twice as much? Tell whether you think this difference-or the lack of one-seems fair.
Answer:
The answer is less than twice as much.
Explanation:
When the income doubles, the personal tax liability also doubles. However, because I have more dependents on my household, I'm able to get tax reductions to take care of the dependents.
A certain light bulb consumes 200J of electrical energy per second, but only emits 25J of light energy per second. Calculate the efficiency of this bulb.
Answer:
The answer is 12.5%
Explanation:
The efficiency of a light bulb is:
Light energy comes out of the bulb / Electrical energy that was put in
= 25J / 200J = 12.5%
What is the average velocity of atoms in 2.00 mol of neon (a monatomic gas)
at 308 K? Use the equation: -mv2
2
For m, use 0.02000 kg. Remember that R = 8.31 J/(mol-K).
= ER
3
2
nRT
A. 1540 m/s
B. 876 m/s
C. 87.6 m/s
O D. 15,400 m/s
Answer:
v = 876 m/s
Explanation:
It is given that,
Number of mol of Neon is 2 mol
Temperature, T = 308 K
Mass, m = 0.02 kg
Value of R - 8.31 J/mol-K
We need to find the average velocity of atoms in 2.00 mol of neon. Neon is a monoatomic gas. Let v is the velocity. So,
[tex]\dfrac{1}{2}mv^2=\dfrac{3}{2}nRT\\\\v=\sqrt{\dfrac{3nRT}{m}} \\\\v=\sqrt{\dfrac{3\times 2\times 8.314\times 308}{0.02}} \\\\v=876.47\ m/s[/tex]
So, the correct option is (B).
why can the suns rays cause a burn but the light from a flashlight cannot harm your skin?
if a source of sound waves is rabidly approaching a person the sound heard by the person appears to have?
Answer:
have a frequency. higher than the frequency actually produced by the source.
Explanation:
Answer:
If a source of sound waves is rapidly approaching a person, the sound heard by the person appears to have - a pitch lower than the original pitch.
There are traits like blood type and eye color, and others like speaking English or having a scar. What are the terms used to describe these different types of traits? How are each defined?
PLEASE ONLY ANSWER IF YOU KNOW
WILL GIVE BRAINLEIST
depending on Genetics the father genes depend on everything because they give most of the heredity and genetics to the child more than the mother does
I need help with this question I added an image so y’all can see !
Answer:
a) .66
Explanation:
from (0,4) to (3,6)
the slope would be
[tex] \frac{2}{3} [/tex]
when diving the fraction the half slope is .66666...
In the diagram, q1= +8.0 C, q2= +3.5 C, and q3 = -2.5 C. q1 to q2 is 0.10 m, q2 to q3 is 0.15 m. What is the net force on q2? Label sign for charges (+ or -). (Unit = N). pls help?
Answer:
f(t) = 28,7 [N]
Explanation: IMPORTANT NOTE: IN PROBLEM STATEMENT CHARGES ARE IN C (COULOMBS) AND IN THE DIAGRAM IN μC. WE ASSUME CHARGES ARE IN μC.
The net force on +q₂ is the sum of the force of +q₁ on +q₂ ( is a repulsion force since charges of equal sign repel each other ) and the force of -q₃ on +q₂ ( is an attraction force, opposite sign charges attract each other)
The two forces have the same direction to the right of charge q₂, we have to add them
Then
f(t) = f₁₂ + f₃₂
f₁₂ = K * ( q₁*q₂ ) / (0,1)²
q₁ = + 8 μC then q₁ = 8*10⁻⁶ C
q₂ = + 3,5 μC then q₂ = 3,5 *10⁻⁶ C
K = 9*10⁹ [ N*m² /C²]
f₁₂ = 9*10⁹ * 8*3,5*10⁻¹²/ 1*10⁻² [ N*m² /C²]* C*C/m²
f₁₂ = 252*10⁻¹ [N]
f₁₂ = 25,2 [N]
f₃₂ = 9*10⁹*3,5*10⁻⁶*2,5*10⁻⁶ /(0,15)²
f₃₂ = 78,75*10⁻³/ 2,25*10⁻²
f₃₂ = 35 *10⁻¹
f₃₂ = 3,5 [N]
f(t) = 28,7 [N]
Answer:
facts
Explanation:
Find the x-component of this vector: 47.3 m 39.4 ° Remember, angles are measured from the + x axis. x-component (m)
The x-component of the vector is 36.55 m.
Components of vectorsThe components of a vector include both x and y components. The x-component is determined along x-axis, while y-component is determined along y-axis.
Vx = Vcosθ
Vy = Vsinθ
where;
Vx is the x-component of the vectorVy is the y-component of the vectorX-components of the vectorThe x-component of the vector is calculated as follows;
x = 47.3 x cos(39.4)
x = 36.55 m
Thus, the x-component of the vector is 36.55 m.
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PLS HELP. I WILL MARK U THE BRAINLIEST IF U ANSWER EVERYTHING STEP BY STEP AND CORRECTLY.
Answer:
Distance = 15m
Displacement = 5m
Explanation:
For distance add the values
For displacement use Pythagoras formula
