Answer:
C always
Explanation:
The force of friction between the object and the surface decrease immediately after the object starts to move.
What is friction?The force preventing solid surfaces, fluid layers, and material components from sliding past one another is known as friction.
The definition of static friction is: The resistance people feel when they attempt to move a stationary object across a surface without actually causing any relative motion between their body and the surface they are moving the object across.
The resistance that is formed between any two items when they are sliding against one another is known as sliding friction.
It is experimentally proved that the force of friction between the object and the surface decrease, immediately after the object starts to move.
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If a rock falls from a cliff, at what point are its kinetic energy and its potential energy the same? Ignore air resistance.
Answer:
The gravitational potential energy it had from being above the ground is converted to kinetic energy as the rock falls. As kinetic energy increases, the velocity of the rock will also increase.
Explanation:
a. How far does a 100-newton force have to move to do 1,000 joules
of work?
b. An electric hoist does 500 joules of work lifting a crate 2 meters. How
much force does the hoist use?
c. An athlete does one push-up. In the process, she moves half of her body
weight, 250 newtons, a distance of 20 centimeters. This distance is the
distance her center of gravity moves when she fully extends her arms. How
much work did she do after one push-up?
d. You decide to push on a brick wall with all your might for 5 minutes. You
push so hard that you begin to sweat. However, the wall does not move. If
you end up pushing with a force of 500 newtons, how much work did you
do?
Work done by a force is given as the product of force and the distance moved by the force.
What is work done?Work done is the product of force and the distance moved by the the force.
Work done = Force × distanceThus, distance required by the 100 N force is given as:
Distance = work done/forceDistance = 1000/100 = 10 m
Distance to be moved is 10 m.
Force applied = work done/ distance
Force applied by the hoist = 500/2
Force applied by the hoist = 250 N
Distance moved in one push-up = 25 cm = 0.25 m
Work done by the athlete after one push-up = 250 × 0.25 m
Work done by the athlete = 62.5 J
Distance moved by the force = 0 m
Work done = 500 × 0 = 0 N
Therefore, for work to be done, force has to move a distance.
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What are the basic si units for the speed of light?.
Community psychologists are not
concerned with worker stress factors.
True
False
If a 20g bullet has a momentum of 8kg calculate its velocity
Explanation:
I hope this helps, you can ask any questions for clarification
Plant cells contain both chloroplasts and mitochondria. Compare and contrast the functions
of these organelles.
Answer:
Mitochondria and chloroplast are organelles found in a plant cell. However, chloroplast is absent in an animal but mitochondria is found in both. Mitochondria generates energy for the cell in the form of ATP using oxygen and nutrients. Chloroplast is the site for photosynthesis in a plant cell.
During which phase of the moon can a lunar eclipse happen?.
If a wave has a frequency of 50 Hz and a wavelength of 2 meters.
Find its speed.
Answer:
100 m/s
Explanation:
here we use the wave equation which states that the velocity is equal to the product of the frequency and the wavelength.
so v = 50 × 2
v = 100 m/s
What happens to the signal inside of the cell phone? Describe at least two kinds of transformations or changes that happen to the signal inside of cell phone.
Answer:
When you're talking on a cell phone, it converts your voice into a signal that is transmitted via radio waves to the nearest cell tower. The cell tower then relays the radio wave back to the person you're speaking to, converting it first to a signal and then back to sound again.
Explanation:
no explanation for you
but the answer is in the top!
what the equation for speed?
Answer:
Speed Formula:
[tex]s = \frac{d}{t} [/tex]
1. A woman shuts her summer cottage up in September and returns to June. No one has entered the cottage in the meantime
Explain what she is likely to find, in terms of the second law of thermodynamics.
The hot summer cottage she left in September will still be hot when she returns in June as long as no one enters it (Isolated).
What is second law of thermodynamics?The second law of thermodynamics states that, hot things always cool unless you do something to stop them. Or the total entropy of an isolated system can never decrease.
In other words, not all heat energy can be converted into work in a cyclic process.
Therefore, we can conclude that when the woman returns, the hot summer cottage she left in September will still be hot when she returns in June as long as no one enters it (Isolated).
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Neutrons are also known as____
neutrinos
photons
alpha particles
beta particles
Answer:
Beta Particles
Explanation:
What happens if you suspend a bar magnet so that it can swing freely.
A train travels north at 103 km/hr. Is this an example of speed, velocity, or acceleration?
Answer:
velocity
Explanation:
when a speed is given with a direction it is velocity
Answer:
Velocity
Explanation:
Velocity is the rate, and direction of an objects movement.
Speed is the rate of and objects movement, no certain direction.
Acceleration is the rate when velocity changes over time, it can both increase and decrease, and it has both speed and direction.
I hope this helps! Have a great day!
Your Murderer~
Suppose that your car is stuck on ice. The wheels spin, but the car does not move. Your friend suggests that you let the air out of the tires to increase the amount of friction. What are some reasons your friend might think this? Discuss whether or not these reasons are consistent with what you have learned about friction.
Explanation:
The center of mass of a system acted on only by internal forces cannot accelerate. without friction a car cannot move. This is a consequence of Newton's third law
Koto traveled 5,000 meters north from her house with an average velocity of 4.5 m/s. what was the time of her trip? (there are 60 seconds in 1 minute.) 18.5 minutes 20.4 minutes 2 hours 3 hours
Answer:
20.4 minutes
Explanation:
5000 m / (4 m/s) = 1250 seconds
1250 seconds / 60 seconds/minute = ~ 20.4 minutes
Time taken by Koto during her trip is (a) 18.5 minutes.
The details given in the question:The distance travelled by Koto = 5000 meters
Koto's average velocity = 4.5 meters/second
To calculate time of Koto's trip following formulae is used:
Time = Distance/Velcoity
Time = 5000 meters/4.5 meters*[tex]Seconds^{-1}[/tex]
Time = 1111.11 seconds or 18.5 minutes
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Whoever is good at physics, can you help me with these questions?
Answer:
i honestly do not know the awnser , im just setting up my brainly account
Answer:
Q)32) What is the unit of intensity of sound
Ans)Decibel
Q)33) Relate amplitude and distance to the intensity and loudness of sound
Ans)The average amount of energy passing through a unit area per unit of time in a specified direction is called the intensity of the wave. As the amplitude of the sound wave increases, the intensity of the sound increases. (i can't find the answer for distance and loudness i can't find it on g....o...o....g....l.....e and my textbook u will have to search it on ur own sorry)
Q)34) What is the pitch of sound
Pitch is the rise and fall of our voice when we speak. It is the characteristic of sound by which we can distinguish the sounds of the same loudness. Types: Pitch is generally of two types, high pitch and low pitch. High Pitch: The higher the frequency of the sound, the higher will be the pitch.
Q)35) How is pitch of sound related to its frequency of sound waves?
The sensation of a frequency is commonly referred to as the pitch of a sound. The pitch of the sound we hear depends on the frequency of the sound wave. A high frequency sound wave has a high pitch, and a low frequency sound has a low pitch.
Q)36) Define the Doppler effect?
The apparent change in the frequency of sound due to the relative motion between the source and the observer is called the Doppler effect.
Q)37) Explain why the doppler effect occurs
The Doppler effect, or Doppler shift, occurs when the movement of an observer relative to a source (or vice versa) causes a change in wavelength or frequency.
Sorry i can't find the last one i will try to search it afterwards
What are nonrenewable resources?
They are natural resources that are in limited supply and can easily run out.
They are natural resources that are in abundant supply or that can replenish themselves.
They are abundant natural resources that humans do not have to recycle or reuse.
They are artificial resources that humans use but are not able to be recycled or reused
Answer:
No. 1 is the correct answer.
Explanation:
The natural resources which deplets after long and continious use and are unable to be recreated/ takes a lot of time to renew are non renewable resources
Can someone help me with this please :(
Answer:
it should be iii) Upthrust exerted on P is more than the upthrust exerted on Q
Under what circumstances can differentiation occur in a planet?.
1) anything that has mass and takes up space is called
A. Tissues
B. Mass
C. Matter
D. Atomic number
E. Weight
2) mechanical energy is
A. Found in machinery only
B. Usually measured at the atomic level
C. The sum of the chemical and thermal energy of an object
D. The sum of the kinetic and potential energy of an object
( please answer it guys i really bad at my physics TnT))
[tex]\qquad \qquad \huge \pink {\sf{☁Answer☁}} \\ \\ [/tex]
Anything that has mass and takes up space is :-[tex]\pink{\boxed{\sf{↪Option.c↩}}}[/tex]
→Matter✓
mechanical energy is[tex]\pink{\boxed{\sf{↪Option.d↩}}}[/tex]
→The sum of the kinetic and potential energy of an object✓
___________________☃️[tex]\sf{\:мѕнαcкεя\: ♪...}[/tex]
A tow truck pulls a 3500 kg mazda car out of the mud. The car is moved 20 M in 4 seconds by the truck. What is the work done by the tow truck
Answer:
W = F * S one does not know the work performed because one does not know what force produced the resulting work. Neither can one calculate the power required because P = W / t (work / time)
One only knows the distance and the time but not the force required.
A scientist shines light from a source onto a piece of metal, and no electrons are released by the metal. Increasing the intensity of the light source does not change this result. What is this effect, and how do scientists explain it?
This is the Doppler effect, and it is best explained by the wave model of light.,
This is the Doppler effect, and it is best explained by the particle model of light.
This is the photoelectric effect, and it is best explained by the wave model of light.,
This is the photoelectric effect, and it is best explained by the particle model of light.
This is the photoelectric effect, and it is best explained by the particle model of light.
What is the photoelectric effect?The photoelectric effect refers to the emission of negatively charged particles and electromagnetic radiation that hits an object.
The photoelectric effect shows how electrons can be released from a given object when this material is absorbing electromagnetic radiation.
The photoelectric effect is a fundamental piece of evidence for understanding the nature of light particles.
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help pls i been stuck on this for 40 mins already
Answer:
See below
Explanation:
At A they add together (they are both positive)= construct
At B they destruct ( one is neg and one is pos)
c destruct d destruct e construct (both neg)
The summary identifies the location(s) in the electric field where the field strength is the greatest, explains how the electric field strength changes due to a change in position, describes the movements of both a positive and a negative test charge placed in the electric field, predicts how the electric field changes due to an increase and decrease in voltage, and predicts how the electric field changes due to an increase and decrease in the distance between leads.
(a) When the voltage increases, the electric field increases, and vice versa.
(b) When the distance of the charge increases, the electric field strength decreases, and vice versa.
Electric field directionThe direction of the electric field depends on the direction of the positive charge, electric field is always directed opposite to positive charge.
Relationship between electric field and voltageThe potential of a unit charge is the product of the electric field strength and the distance of the charge.
V = Ed
E = V/d
Thus, when the voltage increases, the electric field increases, and when the voltage decreases, the electric field decreases.
Also, when the distance of the charge increases, the electric field strength decreases, and the distance decreases, the electric field strength increases.
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lightnig can be described by which statement
Answer:
Lightning can be described by the flow of electric charges between the cloud and the ground.
Is the sun making the side walk a chemical or phsical change
Answer: it is chemical .
Explanation: because chemical change that results in the formation of new chemical substances. During the sun tanning, both vitamin D and melanin are produced. your welcome <3 .
Help, Please...Please Please, please please please, please, please please please please, please
Answer: i thinks Its C
Explanation:
How long is a wave that has a frequency of 2.70X102 Hz and is moving through copper at 3560 m/s?
The wavelength of a wave that has a frequency of 2.70X102 Hz and is moving through copper at 3560 m/s is 13.19m.
How to calculate wavelength?The wavelength of a wave can be calculated using the following formula:
λ = v/f
Where;
λ = wavelength (m)v = speed (m/s)f = frequency (Hz)According to this question, a wave has a frequency of 2.70X10² Hz and is moving through copper at 3560 m/s. The wavelength is calculated as follows:
λ = 3560/270
λ = 13.19m
Therefore, the wavelength of a wave that has a frequency of 2.70X102 Hz and is moving through copper at 3560 m/s is 13.19m.
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5. How much time does it take for a bird flying at a speed of 45 kilometers per hour to travel a
distance of 1800 kilometers
Answer:
[tex]40h[/tex]
Explanation:
Use the velocity formula to solve
[tex]v = \frac{d}{t}[/tex]
In this question, you are given velocity [tex]v = 45km/h[/tex], and you are given a distance, [tex]d = 1800km[/tex]. Time in this question is what you'll need to find.
Start by rearranging the velocity formula, to isolate for t.
[tex]v = \frac{d}{t}[/tex]
Start by multiplying both sides by t
[tex]v(t) = \frac{d}{t}(t)\\\\vt = d[/tex]
Then divide both sides by v.
[tex]vt\frac{1}{v} = d/v\\ \\t = \frac{d}{v}[/tex]
Now that you've isolated for time, sub in your values and calculate.
[tex]t = \frac{d}{v} = \frac{1800km}{45km/h} = 40 h[/tex]