Answer:
53 kg m/s
Explanation:
Momentum = mass × velocity
p = mv
p = (8.9 kg) (6.0 m/s)
p = 53.4 kg m/s
Rounded to 2 significant figures, the momentum is 53 kg m/s.
Which of the following is an example of a chemical change
Electron are _____ charged particles
Answer:
negatively
Explanation:
hope this can help u :3
Answer:
negatively
Explanation:
Why is a device never 100% efficient? *
a) Mechanical Advantage
b) Work
c) Friction
d) Speed Ratio
brainliest for best answer, asap plz
for science lovers!!
1. Of the following, the one that is not an example of a suspension is
a. Milk
b. Milk of magnesia
c. Sand in water
d. Sugar in water
2. The word used to represent a chemical reaction is a/an
a. Atom
b. Formula
c. Equation
d. Symbol
3. When two similarly charged objects are brought close together, they
a. Repel each other
b. Have no effect on each other
c. Stick to each other
d. Attract each other
4. An element common to all acids is
a. Chlorine
b. Hydrogen
c. Nitrogen
d. Oxygen
5. Atoms of the same element that differ slightly in mass are called
a. Ions
b. Isotopes
c. Neutrons
d. Positrons
6. In general, salts
a. Contain hydroxide ions
b. Contain hydrogen ions
c. Are ionic compounds
d. Turn blue litmus red.
7. A dye used to test the acidity of a substance is
a. Litmus
b. Magnesium sulfate
c. Sodium chloride
d. Sodium hydroxide
8. The central portion of an atom is called the
a. Electron
b. Nucleus
c. Ring
d. Shell
9. Sugar is poured into a glass of water and stirred. In this example the sugar is the
a. Solution
b. Solvent
c. Solute
d. Alcohol
10. Which of the following is characterized by a sour taste?
a. Bases
b. Acids
c. Salts
d. Compounds
11. Which of the following is characterized by a bitter taste and turn lithmus blue?
a. Bases
b. Acids
c. Compounds
d. Elements
12. The force of gravity on an object is called
a. Density
b. Mass
c. Volume
d. Weight
13. The liquid referred to as the “universal solvent” is
a. Alcohol.
b. Benzene.
c. Oil.
d. Water.
14. A statement that proposes a cause-and-effect relationship between two variables is called:
a. Conclusion.
b. Fair test.
c. Hypothesis.
d. Theory
15. Any substance that has mass and occupies space is called
a. A gas
b. A liquid
c. Matter
d. A solid
16. When the numbers of electrons and protons in a sample of matter are equal, the matter is
a. Insulated.
b. Negatively charged.
c. Neutral.
d. Positively charged.
17. Which of the following is most important when judging the quality of a scientific theory?
a. The quality and reliability of data that support the theory
b. The amount of detail provided in the theory
c. How recently the theory has been published
d. The respectability of the scientists setting forth the theory
18. Substances that cannot be decomposed to any simpler substances are called
a. Compounds.
b. Elements.
c. Mixtures.
d. None of the above.
19. When the air in a bell jar containing a ringing bell is removed, the sound decreases because
a. The removal of the air prevents electric current from flowing
b. Sound cannot travel through the air
c. Sound cannot travel through glass
d. Sound cannot travel in a vacuum
20. An element common to all acids is
a. Chlorine.
b. Oxygen.
c. Nitrogen.
d. Hydrogen.
21. The amount of matter in an object is best expressed by its
a. Density
b. Mass
c. Volume
d. Weight
22. A substance that increases the rate of a reaction is a
a. Liquid
b. Gas
c. Catalyst
d. Solid
Answer: 1. C
Explanation: 2. C
A model of an atom is useful when it
Select one:
O a. is shown only as the planetary model
b. shows exactly what an atom looks like
c. helps to visualize processes that cannot be seen with our eyes
d. magnifies what the eye can't see
A piston has an area of 4 m2 and needs 20 N of force to push it down. What is the pressure?P=F/A *
A) 5 Pa
B) 0.2 Pa
C) 80 Pa
D) 20 Pa
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for besties with scienceeee!! asap plzz
6. How is work related to kinetic energy?
Answer: Energy should be transferred to an object in order to move it. This amount of energy transferred by the force to move an object is called work or work done. Thus, the relation between Work and Energy is direct. That is, the difference in the Kinetic energy of an object is work done by an object. OR
The principle of work and kinetic energy (also known as the work-energy theorem) states that the work done by the sum of all forces acting on a particle equals the change in the kinetic energy of the particle. The kinetic energy of the block increases as a result by the amount of work.
Explanation:
What happens to sound waves after they are received by our ears?
Answer:
Our ears perceive then sound then it is transmitted to our brain where it is processed into something we can respond to. This all happens in less than a second and we are unaware that we are doing it.
Explanation:
The sound wave bounces off of the ear drum into the inner ear.
Answer:
Sound waves travel from the outer ear and in through the auditory canal, causing the eardrum to vibrate. This in turn causes three small bones in the middle ear to move. The vibrations move through the fluid in the cochlea in the inner ear, stimulating thousands of tiny hair cells.
What will happen if a circular coil is used instead of a rectangular coil as the conducting coil in a generator?
Explanation:
when we use our circular coil, the magnetic field will always be perpendicular to the area vector.thus, due to this, sin wt gives sin 90 degree and that gives 1, giving maximum linking of flux associated with the coil at any position .
Answer:
When we use a circular coil, the magnetic field will always be perpendicular to the area vector. Thus, due to this, sinωt gives sin90∘ and that gives 1 , giving maximum linking of flux associated with the coil at any position.
Explanation:
1. Suppose you had come along before Mendeleev and were tasked with
organizing the elements into a pattern others could understand. Describe your
arrangement and how you would determine where elements would be placed.
Can you think of any problems your design might create?
2. The first periodic table was organized according to atomic mass, but the
current periodic table is arranged according to atomic number. What is the
difference between atomic mass and atomic number, and why is the atomic
number now the basis for the periodic table?
3. How would the periodic table look differently if it was arranged according to
atomic mass? Focus on Periods 1-4 to complete your answer.
Answer:
1. There would be two different tables, one arranged by mass and the second arranged by the chemical reactions the elements are known for
2. a. The difference is that the atomic mass is fixed and is 2 or more times the atomic number which is variable
b. The atomic number is the bases of the periodic table because it reflects the unique identity as well as the chemical and physical properties of the atoms more than the atomic number
3. The table formed by the atomic mass is not representative of the chemical properties of the elements
Explanation:
1. The elements would have been arranged by mass and by order of reaction such that there would be two tables where the first table will list all the known elements arranged by mass and the second table will group the elements in the order in which they can react or the kinds of compounds they can form such as oxides, nitrides etc
2. a. The atomic number, Z, is determined by the definitive number of protons contained in the nucleus of an atom and it is used for the classification of an atom as a particular element based on the its equivalent atomic number
The atomic number defines the chemical behavior of an an element because it is equal to the number of electrons present in a neutral atom
The atomic mass or mass number, A, is the total of the mass of the protons and the neutrons present in an atom
The neutron is electrically neutral, allowing its quantity to vary without significantly impacting on the chemical behavior of the atom, hence two different elements can have the same number of neutrons
Therefore, the difference is that the atomic mass is fixed and is 2 or more times the atomic number which is variable
b. The atomic number is the bases of the periodic table because it reflects the unique identity as well as the chemical and physical properties of the atoms more than the atomic number
3. If the periodic table was arranged according to the atomic mass, we would have;
Groups
H
He Li B C O F Na
Be N Ne Mg S Ar Sc
O Si Ca Ti Zn Se
It is seen that the above table is not representative of the chemical properties of the elements.
4. How does a molecule differ from an atom? (4 points)
____ charges are attract each other
Answer:
One positive and one negative
Help.
Why do scientists believe that global warming is happening?
Question 5(Multiple Choice Worth 4 points) (01.04 MC) Which of the following correctly describes the relationship between speed and velocity? Speed is the change in velocity over time; velocity is distance plus direction. Speed is the change in distance over time; velocity is speed plus direction. Speed is distance plus direction; velocity is speed plus time. Speed is the change in acceleration; velocity is distance over time.
Answer:
Speed is the change in distance over time; velocity is speed plus directionExplanation:
Speed is defined as the change in distance covered by a body with respect to time while velocity the change in displacement of a body with respect to time. Speed is a scalar quantity since it does not specifies direction while velocity is a vector quantity because it specifies both magnitude and direction.
Speed can only be equal to the velocity if it also specifies direction.
Based on the definition above, it can be concluded that speed is the change in distance over time and velocity is speed plus direction.
Answer:
Speed is the change in distance over time; velocity is speed plus direction.
Explanation:
I did it and got the test right
A large force will cause_______ acceleration than a small force
Answer:
A large force will produce more acceleration than a small force acting on the same object.
M
An object has a mass of 5.52 g and a volume of 12 mL. What is the density of the object
Answer:
0.46 g/mL
Explanation:
Density can be found using the following formula.
[tex]d=\frac{m}{v}[/tex]
where d is density, m is mass, and v is volume.
We know that the object has a mass of 5.52 grams and a volume of 12 milliliters.
m=5.52 g
v=12 mL
Substitute these values into the formula.
[tex]d=\frac{5.52 g}{12 mL}[/tex]
Divide 5.52 by 12
5.52/12=0.46
d=0.46 g/mL
The density of the object is 0.46 g/mL, and option C is correct.
6. The peak value of an AC sine wave is
120 V. What's the effective value
(rounded)?
A. 65 V
B. 85 V
C. 200 V
D. 140 V
Answer:
B. 85 V
Explanation:
E(rms) = E(peak-to-peak) / squareroot(2)
E(rms) = 120V / 1.414 = 84.9 V
(When rounded) = 85 V
The correct option about peak value and effective value of AC sine wave is, “85 V”.
What are the differentiating factors between peak value and effective value?Peak value is also known as maximum value.Effective value is also known as RMS (Root Mean Square) value.Maximum value attained by Alternating quantity is defined as Peak value.The square root of average of the square of quantity during a complete cycle is defined as Effective Value. How to do the conversion between peak value and effective value?To convert peak value to effective value, divide the peak value by √2 and the result will be the effective value.To convert effective value to peak value, multiply the effective value with √2 and the result will be the peak value.How to solve this question?Peak value = 120 V (Given)
Effective value = Peak value ÷ √2
Effective value = 120 ÷ √2
Effective value = 85 V (approximately)
Thus, we can conclude that by dividing the peak value by √2, we will get effective value and multiplying the effective value with √2 will give peak value as result.
Learn more about peak value and effective value here:
https://brainly.com/question/15109247
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A plane increases its speed from 450 km/hr to 750 km/hr in 0.30 hour. What is its acceleration?
Answer:
The acceleration is found as:
a = 1000 km/h²
Explanation:
Initial speed of the plane = 450 km/h
Final speed of the plane = 750 km/h
Time taken = 0.3 h
Acceleration can be defined as the change of speed of the object divided by the time taken to bring that change
Acceleration is given as:
[tex]a=\frac{v_f-v_i}{t}[/tex]
where v(f) = 750 km/h , v(i) = 450 km/h , t = 0.3 h
Substitute the values in the equation of acceleration
[tex]a= \frac{750-450}{0.3}\\a=\frac{300}{0.3}\\a=1000 km/h^2[/tex]
This is the found result
Light ray A moves from air to water. Part of ray A is reflected at the air-water boundary. Which arrow in the image is the reflected ray?
E
OA. B
OB.
С
OC.
D
OD. E
Answer:
A. B
Explanation:
The image has been attached.
Reflected ray refers to the ray of light which is reflected back after striking a surface that is non-permeable.
The ray of light which is reflected before the ray touches the surface is said to the incident ray.
According to the given image, ray B is the reflected ray. Ray B is reflected in the air after the ray A strikes at the surface of the water.
B
Explanation:
Since mirrors reflect things, when you shine light at a mirror, it will bounce off of the mirror, or reflect, and shine the opposite direction of where the original light is pointed. The answer would be B because light doesn't go through the mirror, or run along it.
Think of when you through a basketball on the ground. If you bounce it at an angle, it won't just come back to you in the same angle. It will keep bouncing at the same angle you through it. This is pretty much what describes the relationship between ray A and ray B.
HOPE THIS HELPS!!!!!
A lens with f= 10.0 cm is held
45.0 cm from an object. What is
the image distance?
(Unit = cm)
it is not 12 cm.
Answer:
8.2 cm
Explanation:
1/f = 1/so + 1/si
1/10 = 1/45 + 1/si
1/si = 1/10 - 1/45
1/si = 9/90 - 2/90
1/si = 7/90
si = 90/7 = 12.86 cm.
since you said that the answer was not 12 them the lens must be concave with negative (minus) focal length
1/f = 1/so + 1/si
- 1/10 = 1/45 + 1/si
1/si = - 1/10 - 1/45
1/si = -9/90 - 2/90
1/si = -11/90
si = -90/11 = - 8.2 cm
- (read: minus or negative sign) indicates the image is in the same side of the object
hope its true and can help you
Answer:
1/f = 1/u + 1/v
f=10cm
u=45cm
v=? (Image distance)
1/v = 1/f - 1/u
1/v = 1/10 - 1/45
1/v = (9-2)÷ 90
1/v = 7/90
:. v = 90/7
v=12.86cm(image distance)
A blow dryer transfers thermal energy mainly by
A. conduction
B. convection
C. radiation
D. specific heat
Answer:
B
Explanation:
Through air
Answer:
thermal conduction I assume
Explanation:
why because the thermal Insulator: a material that conducts thermal energy poorly. Gives off heat
A mover uses a ramp to load a crate of nails onto a truck. The crate, which must be lifted 1.5 m from the street to the bed of the truck, is pushed along the length of the ramp. If the ramp is 4.5 m long and friction between the ramp and crate can be ignored, what is the mechanical advantage of the ramp?
Answer: M.A = 3
Explanation:
A ramp is an example of an inclined plain. Where the
Height H = 1.5 m
Length L = 4.5 m
Mechanical advantage of a machine is the ratio of the load to effort. While mechanical advantage M.A of an inclined plain is the ratio of the length of the plain to the height of the plain.
M.A = L/H
Substitute the values of L and H into the formula
M.A = 4.5/1.5 = 3
The mechanical advantage of the ramp is 3
Do you think a population besides the moon jellies’ consumer population (sea turtles) and resource population (zooplankton) could have caused the moon jelly population to increase in size?
Answer:
I didn't quite understand your question, but the moon jelly population will increase if there are either more zooplankton or less sea turtles.
More zooplankton means more food => higher population
Less sea turtles means that the moon jelly will be lest often consumed => higher population
Answer: Yes because the Orca will start to eat the moon jellies
Explanation: When the Sea Turtles start to get very low on population the Moon jellies are next in line also the sea turtles eat the moon jellies and since they eat the moon jellies the sea turtle has a bit of that taste in them so they will taste alike to the sea turtles.
why does a bouncing ball have a greater change in momentum than a ball that is just caught
If the ball bounces, then there is an additional velocity change sending the ball back upwards opposite the original direction. Thus, for the same collision time, bouncing involves a greater velocity change, a greater momentum change, and therefore a greater impulse.
Answer:
because with the change in momentum the velocity goes to zero. (more info below)
Explanation:
Momentum is the velocity change multiplied by the mass. When you think about it, bouncing an object means it comes back from anything it bounced against, giving it a velocity that is negative. This means that the velocity change for bouncing is greater than for colliding, as the velocity goes to zero in an inelastic collision like the one described.
hope this helped!
How does the electric force between two charged objects change when the
distance between the objects increases?
Answer:
When the electric force between two charged objects change, the distance between the objects increases in Iicreasing the separation distance between objects and decreases the force of attraction or repulsion between objects.
Hope it helps.
What protects you from getting a shock when you touch a live wire?
A grounding wire
B circuit breaker
C fuse
D insulation
Answer:
Insulation protects you. Thats because the insulation will make a wall almost where the electrons cannot travel through. So when you touch the insulation on a live wire your SAFE. Insulations may include rubber, wood, and air.
Answer:
I'm pretty sure its insulation
Explanation:
Which diagram is the best model for a solid ?
If earth had two moons, how might this affect the way we see eclipses here on earth?
Which best describes Earth’s magnetic field lines? The field lines go out of Earth near the South Pole, enter Earth in the North Pole, and are aligned with the geographic poles. The field lines go out of Earth near the South Pole, enter Earth in the North Pole, and are not aligned with the geographic poles. The field lines go out of Earth near the North Pole, enter Earth in the South Pole, and are aligned with the geographic poles. The field lines go out of Earth near the North Pole, enter Earth in the South Pole, and are not aligned with the geographic poles.
Answer:
b
Explanation:
did the quiz
Answer:
(B) The field lines go out of Earth near the South Pole, enter Earth in the North Pole, and are not aligned with the geographic poles.
Explanation:
What scientific evidence supports the Big Bang theory?
Universe expansion
Redshift
Composition of the universe
All of the above
None of the above
Answer:A universe expansion
Explanation:
The earliest and most direct observational evidence of the validity of the theory are the expansion of the universe according to Hubble's law (as indicated by the redshifts of galaxies), discovery and measurement of the cosmic microwave background and the relative abundances of light elements produced by BBN.