Starting initially at rest at t=0, a subway car accelerates to 29 m/s over a period of 6 seconds, and then begins to brake. Forty-eight (total) seconds after starting, it is moving at 12 m/s . What is its average acceleration in this 48-s interval?

Answers

Answer 1
First, let's find the acceleration for the 6 s-interval. Since it started at rest, the initial velocity is 0. Then, the acceleration would be 

a = (29 - 0)/6 = 4.833 m/s²

For the rest of the interval, the time would be 48 s - 6 s = 42 s. The initial velocity at this point is 29 m/s and the final velocity is at 12 m/s. So the acceleration is

a = (12 - 29)/42 = -0.405 m/s²

Finally, the average acceleration is
Average acceleration = (4.833 + ⁻0.405)/2 = 2.214 m/s²

Related Questions

A 0.05-kg car starts from rest at a height of 0.95 m. Assuming no friction, what is the kinetic energy of the car when it reaches the bottom of the hill? (Assume g = 9.81 m/s2.)
A. 0.466 J
B. 0.308 J
C. 4.317 J
D. 0.0475 J

Answers

The kinetic energy of the car is A.) 0.466 J

The kinetic energy of the car when it reaches the bottom of the hill is about A. 0.466 J

[tex]\texttt{ }[/tex]

Further explanation

Let's recall Kinetic Energy Formula as follows:

[tex]\large {\boxed{Ek = \frac{1}{2}mv^2} }[/tex]

Ek = Kinetic Energy ( Joule )

m = mass of the object ( kg )

v = speed of the object ( m/s )

Let us now tackle the problem !

[tex]\texttt{ }[/tex]

Given:

mass of the car = m = 0.05 kg

initial speed of toy car = u = 0 m/s

initial height position of the car = h₁ = 0.95 m

final height position of the car = h₂ = 0 m

gravitational acceleration = g = 9.81 m/s²

Asked:

final kinetic energy of the car = Ek₂ = ?

Solution:

We will use Conservation of Energy to solve this problem:

[tex]Ep_1 + Ek_1 = Ep_2 + Ek_2[/tex]

[tex]mgh_1 + \frac{1}{2} m u^2 = mgh_2 + Ek_2[/tex]

[tex]mgh_1 + \frac{1}{2} m (0)^2 = mg(0) + Ek_2[/tex]

[tex]mgh_1 = Ek_2[/tex]

[tex]Ek_2 = 0.05 \times 9.81 \times 0.95[/tex]

[tex]Ek_2 \approx 0.466 \texttt{ J}[/tex]

[tex]\texttt{ }[/tex]

Learn moreImpacts of Gravity : https://brainly.com/question/5330244Effect of Earth’s Gravity on Objects : https://brainly.com/question/8844454The Acceleration Due To Gravity : https://brainly.com/question/4189441Newton's Law of Motion: https://brainly.com/question/10431582Example of Newton's Law: https://brainly.com/question/498822

[tex]\texttt{ }[/tex]

Answer details

Grade: High School

Subject: Physics

Chapter: Energy

A copper water tank of mass 20kg contains 150 kg

Answers

A 75-kg copper block initially at 110°C is dropped into an insulated tank that contains 160 L of water at 15°C. 

Small college has 2523 students in 1994 and 2891 students in 1996 if the enrollment follows a linear growth pattern how many students should the college have in 2006?

Answers

Since it is specified that the relationship is linear, you could think of a linear graph for this. The base year would be 1994. The first point is at (0,2523) while the second point is (2,2891). The slope would be

m = (2891 - 2523)/(2-0) = 184

The slope-intercept form is y = mx + b. Let's substitute (0,2523) to the equation such that
2523 = 184(0)+b
b = 2523

Hence, the equation of the linear graph is y = 184x + 2523. Now, at 2006, x = 2006 - 1994 = 12 years.

y = 184(12) + 2523 = 4,731 students

Two families meet at the park at 10:00am. Each family uses a different way of transportation to get there. The Gonzalez family leaves at 9:00am and drives 90 km on a highway. The Rivera leave at 9:30am and ride the train 30km. What is the average speed for each family’s trip? Which family travels at the faster speed?

Answers


Firstly, we need to make the times and distance equal to compare.

1hr=60mins
Gonz drove 90km in 60mins,so they would drive 45km in 30 mins dividing it by 2.
Because the Rivs had gone 30km in 30mins, Gonz were faster.

For the adverage speed, we should first add the speed of each family in mph , so 90+60, which equals 150 and divide that by 2 because there are 2 speeds so the average speed is 75mph.

P.S English is my second language so tell me if you don't understand something and I will try and explain.

True or false scientific inquiry incorporates many scientific methods

Answers

The statement is true

The correct answer for the given statement above would be option

 A. TRUE.  

Explanation:

Scientific inquiry is a cooperative and coordinated struggle to search out, describe, describe and predict natural phenomena.  Scientific analysis progresses within a continuous process of examination, data collection, interpretation, and interpretation.

A truck driver travels 55 km in 1 hour he then drives a speed of 35 km/h for two hours next he drives 175 km in three hours. what was his average speed?

Answers

first hour = 55 per hour.
= 55

second and third = 35 per hour.
= 70

fourth, fifth and sixth = 175 per hour.
= 525

average speed = (55 + 70 + 525) / 6
= 650 / 6
= 108.33 km per hour

The average speed of a truck driver is 50 km/hr.

Given:

A truck driver travels 55 km in 1 hour he then drives at a speed of 35 km/h for two hours next he drives 175 km in three hours

To find:

The average speed of a truck driver.

Solution:

Distance traveled by a truck driver in 1 hour = 55 km

Speed of a truck driver after in next 2 hours =35 km/hr

Distance traveled by a truck driver in these 2 hours = [tex]35 km/hr \times 2= 70 km[/tex]

Distance traveled by a truck driver in last 3 hours = 175 km

Total distance traveled by truck driver :

[tex]= 55 km + 70 km + 175 km = 300 km[/tex]

Total time taken by the truck:

[tex]=1 hr + 2 hr + 3 hr = 6 hr[/tex]

The average speed of the truck driver:

[tex]=\frac{\text{Total distace covered}}{\text{Total time taken}}\\\\=\frac{300 km}{6 hr}=50 km/hr[/tex]

The average speed of a truck driver is 50 km/hr.

Learn more about average speed here:

brainly.com/question/8819317?referrer=searchResults

write one example of a physical change and one example chemical change

Answers

Physical change = changes the physical properties (more commonly known as it's look)
Chemical change = changes the chemical properties into an entire new chemical form
Examples of physical change would be melting ice cubes or sugar cubes.
Examples of chemical change would be cooking eggs or burning paper because you're changing its chemical properties.

A sunflower turns its head toward sunlight. What triggers this behavior in a sunflower?

Answers

This is triggered by an activity known as heliotropism, or solar tracking. Special motor cells at the bases of the flowerbuds shrink or enlarge as they absorb water, which moves their faces toward the sun.

Answer:

phototropism

I hope this helps

What is a verb phrase

Answers

a verb phrase is a group of words including a verb and its complements, objects, or other modifiers that function acceptably as a verb.
A phrase that includes a verb

two examples of ways that physicists model the physical world

Answers

Answering the question, three examples of ways that physicists model the physical world include:

DiagramsEquations Computer simulations

Computer simulations refer to the reproduction of behavior of a system with the use of a computer to simulate the results of a mathematical model that is linked with the system.

Further Explanation

Computer simulations are a tool that is very useful for mathematical modeling in various natural systems in physics.

Physicists write the rule of our universe using equations. Equations are an aspect of one of the models used by physicists to explain a particular situation.

Physicists use a diagram to convey information. It is a symbolic representation of information with the use of visualization techniques. Diagram provides other means for people to better understand information and process its importance.

Physics predictions about the physical world mainly depend on numerical stimulation, mathematics and empirical observations and Physicists models the physical world based on invariances and laws which are built on mathematical models.

The purpose of physics is to explain or describe everything around us. It described virtually everything around us accurately by deploring the law of physics.

However, physics is considered a natural science because it is based on mathematical analysis which is geared towards findings qualitative physical law for the physical world.

LEARN MORE:

examples of ways that physicists model the physical world https://brainly.com/question/10869755

KEYWORDS:

physicistsphysicsmodelsphysical worldcomputer simulationsdiagramsequations

We have that

Two examples of ways that physicists model the physical world is Through

Equations  FormulationsDiagrams

From the question we are told that

Two examples of ways that physicists model the physical world

Generally

We First define a  Physicists

A physicists is a Scientist,A Physicists is a Scientists that deals meanly on the Discipline of Physics

The Discipline of Physics deal with the interaction between matter and energy and Understanding the working principle of Nature

Therefore

Two examples of ways that physicists model the physical world is Through

Equations  FormulationsDiagrams

For more information on this visit

https://brainly.com/question/23379286?referrer=searchResults

Is there a point at which no more sodium and chloride ions will dissolve? How do you know?

Answers

Yes, this is the saturation point. For sodium chloride, the saturation concentration in pure water is relatively high - you can dump a lot of salt into water before it will precipitate out as a solid at the bottom of the container.

PLZZZZ HELP!!!! What is unusual about organisms in the domain Archaea?


A. They are very large.
B. Their rate of reproduction is very fast.
C. They are complex, multicellular organisms.
D. They live in extreme environmental conditions.

Answers

D.
They can live in the smallest areas that no other life form can live in
D. They live in extreme conditions

Archaea are prokaryotic organisms that are adapted to live in the most extreme of environments where no other organisms have the ability to survive. The group of archaea that are adapted to extreme environments such as geysers, cold, alkaline and acidic conditions are known as extremophiles. 

Can someone explain subshell/electron configuration to me?

Answers

There are four layers of these electrons are, s, p, d, and f.

Each one has a certain number of shells, in different shapes, that can hold two electrons.

S- Has one shell, shaped like a circle, so in total can hold 2 electrons.

P- has three shells, shaped like an infinity symbol, so in total can hold 6 electrons

D- has five shells, shaped, err, dunno how to describe it, can hold 10 electrons.

F- has 7 shells, um, even more dunno how to describe it, can hold 14 electrons

There doesn't only have to be one of each shell though. There can be two S levels, and one P level, and no D or F levels.

(search up electron configuration it'll have a chart of the order in which these come in)

Each layer will be stated as Number layer electron number.

For example, the first layer of electron level would be 1, because it's the first layer, S, because that's what the first layer is, and if it was completely filled, 2.

So, 1s2.

If you were going to add another level, which would also be a S level, but it only has one electron, you would say:

2s1,

because it's the second s level and has one electron in it.

And to put the two together, just say:

1s2, 2s1

NOTE: if you were going to add another level, it would be a P level, but it wouldn't be 3p something, it would be 1p something because it is the first electron level.

Another note: if you have three layers of electrons, or just six electrons, you would just say 1p6. (because the P orbital can hold 6 electrons)

Hope this helped!

What are the two factors that determine a material's density?

Answers

Mass and volume are the 2 factors to determine density

Your friend Amanda suffers from a condition that reduces her blood's ability to carry oxygen.which of the following is the name of the condition?

Answers

Amanda might be suffering from a disease called Sickle Cell Anemia. It is an inherited red blood cell disorder.

A force of 20 N acts toward the east. Another force of 27 N acts at the same point toward the west. What is the magnitude and direction of a third force that produces a resultant of 10 N toward the east?

Answers

Since we are working in one dimension (left right or East West), we don't need to worry about angles! It's just simply a matter of adding things up!

First list out all the forces and add negative (-ive) signs to each of the 'west' forces like this.

20 East + (-27 West) + ? = 10 East

so it's easy to see that 20 + (-27) = -7
So to get to 10 from -7 just do the sum to get 17.
Since 17 is not negative it must be in the direction of East.
So the answer is:
Magnitude = 17 N
Direction = toward the East

an atom's mass number equals the number of

Answers

Answer:

2

Explanation:

calculate the speed of a car in miles per hour that is flashed on a speed camera covering a 20m distance in 0.5 seconds.

Answers

To find speed you must divide distance over time. So divide 20 with 0.5. And the answer is 40. The car is going 40 miles per hour.

What happens when aluminum fills its valence shell?

A. Three electrons are lost, creating Al ^ +3

B. Three electrons are gained, creating Al ^ -3

C. Three electrons are gained, creating Al ^ +3

D. Three electrons are lost, creating Al ^ -3

Answers

i beileve the answer is B

Answer:

Correct answer is B. Three electrons are gained, creating Al ^ -3

Explanation:

Aluminum in its valence shell has 3 electrons, this shell can have a maximun of 6 electrons. Then, to fill its valence shell, 3 electrons must be gained, and then the valence shell would have 6 electrons and would be complete.

If 3 electrons are gained, then Aluminum, would have a charge of -3, since each electron gained gives negative charge to the atom.

Al^ -3  is a ion of aluminum with charge -3.

Describes what happens to the amplitude of a wave as it moves away from its source and why this occurs.

Answers

The amplitude decreases as the energy is lost due to the propagation of the sound waves through the material medium.

Final answer:

The amplitude of a wave decreases as it moves away from its source because the wave's energy is distributed over a greater area. The amplitude's reduction is exponential, with a constant fractional decrease over each unit of distance, but the speed of the wave remains constant.

Explanation:

As a wave moves away from its source, its amplitude typically decreases. This occurs because the energy of the wave is spread over a larger area as it propagates. It is important to note that the amplitude of a wave does not depend on its frequency or speed, but rather on the energy it carries. In the case of a spherical wave, the amplitude decreases because the energy must be shared among more particles in the outer, larger shells of the wavefront, leading to each particle having less energy and thus reducing the amplitude.

Furthermore, the reduction in the amplitude of a wave that undergoes absorption is exponential according to the principle of superposition. This means that for each unit of distance the wave travels, the amplitude decreases by a constant fraction. However, this reduction in energy does not imply that the wave slows down; the speed of the wave remains constant unless the medium through which it is traveling changes.

Suppose you balance a 1.6-kg ball on the tip of your finger, which has an area of 1.1 cm2 .whats the pressure of your finger

Answers

Pressure is define as force per unit area. Mathematically expressed as,
P=F/A.
We are given, a mass of the ball equal to 
m=1.6kg and an Area of 1.1cm2=1.1([tex] 1x10^{4} [/tex])m2
To calculate for the force exerted by the finger to the ball, it is simply equal to the weight of the ball. Mathematically,
F=W
Weight of the ball can be calculated as,
W= ma
where m=mass of the object and a is the acceleration due to gravity (9.8m/s).
Then, the Weight of the ball which is equalt to the force exerted by the finger,
W=F=(1.6 kg x 9.81)=15.696 N
Then Pressure would be,
P=(15.696N/1.1(.1([tex] 1x10^{4} [/tex])m2))
P=142690.91 N/m2=142690.91 Pa


How does physics applied to being a teacher

Answers

Physics uses the language of mathematics to describe the physical world. Mathematics on it's own is just a language. It is a language that is build from logic :)

please rate as brianliest!! thanks!

A cluster of galaxies containing very few galaxies is known as

Answers

Answer is a Poor Cluster.

Answer:

A group of galaxies forms a cluster.There are two types of clusters of galaxies.

Rich clusterPoor cluster

A rich cluster contains more than thousand galaxies.

A poor cluster contains less than thousand galaxies. Milky way is a part of poor cluster- the local group which has more than fifty galaxies.

Thus, a cluster of galaxies containing very few galaxies is known as poor galaxy.

If we use _______ to build the roof of the house, then the temperature inside the house will remain cooler.

Wood,Clay Brick,Iron,Aluminum,Copper,
Nickel

Answers

clay brick
hope this helped!

Answer:

Wood and clay brick.

Explanation:

If we use wood and clay brick to build the roof of the house the temperature inside the house will remain cooler. As we know wood and clay are non conductor of heat so they not transfer sun's heat inside the room and room remains cooler. On the other hand aluminium, copper and nickel are metals and are good conductor of heat as well they transfer environment's heat inside the room.

7. The outermost electrons of the element vanadium (atomic #23) are in which energy level of the atom? How do you know?

Answers



When writing an electron configuration in orbital form, you put the last noble gas configuration in front, for vanadium it's (Ar). The s-block is filled with its capacity of 2 electrons since vanadium is a regular transition metal. The first d subshell, 4d, puts electrons into the 3rd shell not the outer shell. So it has 2 valence electrons. The exceptions to this rule are chromium, molybdenum, copper, silver and gold, which put one of the s electrons into the d shell.

When falling through the air, which of the following objects will hit the ground first?

a penny
a large poster
a shoe box
a cell phone

Answers

i think the answer is a penny

Answer:

Your answer would be a penny.

Explanation:

Every other answer would have fallen slower because:

A large poster would work as a parachute (which falls slowly.)

A shoe box is empty and big, therefore would fall slowly due to the hollowness and size.

A cell phone is flat and wide (relatively) and would fall slower than the penny EVEN THOUGH it has more weight.

The penny would fall quickly, due to aerodynamics and size. It is small, has weight to it, and other contributing factors prove my point. :)

What Is the mass of 7.50 mol of uranium

Answers

Moles x Mol mass = mass. 
Having looked it up, the mol.mass of U-238 is 238.03g/mol. 
7.50 moles x 238.03g/mol. = 1,785.23g/mol

Final answer:

The mass of 7.50 moles of uranium is 1785.375 g, calculated by multiplying the molar mass of uranium (238.05 g/mol) by the number of moles (7.50).

Explanation:

The question seeks to find the mass of 7.50 moles of uranium. Considering the molar mass of uranium, specifically isotope U-238 which is commonly referred to in problems regarding uranium mass calculations, is 238.05 g/mol. To find the total mass of 7.50 moles of uranium, we use the formula:

Mass = molar mass × number of moles

Thus, the mass of 7.50 mol of uranium is:

238.05 g/mol × 7.50 mol = 1785.375 g

This calculation plainly demonstrates how the molar mass of a substance can be utilized to find the mass of a given number of moles of that substance, an essential concept in chemistry, especially in the field of nuclear chemistry where isotopes such as uranium are frequently discussed.

The moon's phases are caused by (4 points)

A.the alignment of the planets

B.the alignment of the Earth, moon, and sun

C.eclipses of the sun

D.planets moving across the face of the moon

Answers

im pretty sure its b 

The answer is B. The alignment of the moon, earth, and sun.

IMPORTANT QUIZ!!!!!!!

the atomic number of an atom is the number of______.

A.protons and neutrons
B.protons
C.neutrons
D.electrons and neutrons

Answers

b.protons because the atomic number of an element represents the number of protons and electrons

Will adding soap to water affect how many drops of water will fit on a penny?

Please help!

Answers

Yes it can affect the soap of water because soapy is heavy and if you mix it to water it we become heavy.

Final answer:

Adding soap to water decreases its surface tension due to the interaction between soap molecules and water, resulting in fewer drops of water fitting on a penny.

Explanation:

Yes, adding soap to water will affect how many drops of water will fit on a penny. This is because soap reduces the surface tension of water. Normally, water has a high surface tension due to the polar nature of water molecules, which allows it to pile up in drops. However, when soap is added, the soap molecules disrupt the water's cohesive forces by inserting themselves between water molecules.

The ionic-salt end of the soap molecule dissolves in water, while the non-polar hydrocarbon tail sticks out, reducing the attraction between water molecules. This results in lower surface tension, causing the water to spread out more thinly and not pile up as effectively on the surface of a penny. Therefore, you would expect fewer drops of water to fit on a penny after soap has been added to the water.

Other Questions
Given that f(x)= x2+3 and g(x)= x+4/3 solve for (f(g(x)) when x =2 "Should I keep back my opinions at such a time, through fear of giving offense, I should consider myself as guilty of treason towards my country, and of an act of disloyalty toward the Majesty of Heaven, which I revere above all earthly kings." What is the meaning of the word offense as it is used in the first paragraph? A)to make sad B)to make war C)to make happy D)to make angry In the 1600s, william harvey studied reproduction and development. what is the term given to the theory which states that an organism develops from the fertilized egg by a succession of developmental events that lead to an adult? Because the Internet breaks down barriers and lets people explore areas not traditionally meant for them, it can help?A. create better profilesB. destroys bad stereotypes C. make unfair assumptionsD. deter identity thieves During stage 2 of labor, the placenta and umbilical cord are delivered. Please select the best answer from the choices provided. T F Sumner was physically attacked by Brooks in Congress because ___________________ . a.Sumner had attacked abolitionists in Congress.c.Sumner had berated pro-slavery, popular sovereignty supporters.b.Sumner supported the border ruffians in the Kansas Territory.d.Sumner challenged the Fugitive Slave Act and angered pro-slavery supporters. Yeast has many commercial uses in the production of ____. Select all that apply. a.Breadsb.Fuelsc.Sodasd.Wine which material was not used by nubian artisans?A. goldB. ivoryC. steelD. Ebony What is the term for the two sets of chromatids formed in the parent cell? A cafeteria sells 30 drinks every 15 minutes.How many drinks would they sell in 1 hour? Simplify the expression.(1/4)^(-3/2)Please show how to do the problem. Managers can use overt integrity tests to _____. Select the equation that most accurately depicts the word problem. The perimeter of a rectangle is 68 inches. The perimeter equals twice the length of L inches, plus twice the width of 9 inches. an object falls d meters in t seconds. what is the independent variable Farmers in developing countries want the united states to reduce the subsidies that it gives to u.s. farmers because subsidized agricultural products from the united states: question 18 options: Which best describes why a liquid needs a container when a solid does not?Solids fill their containers, and liquids have definite shapes.Solids have definite shapes, and liquids fill their containers.Solids particles do not expand to fill their containers, and liquid particles do.Solids particles expand to fill their containers, and liquid particles do not. Which two of the Harding's cabinet men worked hard to achieve advancements specifically for businesses Which of the following is true about the CENTRAL IDEA in a text?A) It is always clearly stated by the authorB) It is the same as the topic of the passage C) It can be found in the exposition of the passage and only when the author decides it is important to reveal it D) It may be inferred and refers to the overarching main point found throughout the text Cuntas especies de insectos hay en la amazona peruana?approximately 2.5 millionone million species500 thousand species What is 8.478 in expanded form Steam Workshop Downloader