- The school zone in front of your school has a posted speed limit of 25 mi/h, which is about 11 m/s. Let's
examine the stopping of a car in several different situations.
a. The crossing guard holds up her stop sign, and the driver is paying attention well. The car moves at a
constant velocity of 11 m/s for 2.3 seconds while the driver reacts, then slows down at a constant rate
of -4.5 m/s2. What is the stopping distance for the car in this situation?​

Answers

Answer 1

Answer:

s = 38.7 m

Explanation:

First we calculate the distance covered during uniform motion of reaction time.

s₁ = vt

where,

s₁ = distance covered during uniform motion = ?

v = uniform speed = 11 m/s

t = time = 2.3 s

Therefore,

s₁ = (11 m/s)(2.3 s)

s₁ = 25.3 m

Now, we calculate the distance covered during decelerated motion:

2as₂ = Vf² - Vi²

where,

a = deceleration = -4.5 m/s²

s₂ = distance covered during decelerated motion = ?

Vf = Final Velocity = 0 m/s

Vi = Initial Velocity = 11 m/s

Therefore,

2(-4.5 m/s²)s₂ = (0 m/s)² - (11 m/s)²

s₂ = (-121 m²/s²)/(-9 m/s²)

s₂ = 13.4 m

the total distance will be:

s = s₁ + s₂

s = 25.3 m + 13.4 m

s = 38.7 m


Related Questions

what does the "LINE OF BEST FIT" mean?​

Answers

Answer:

Line of best fit refers to a line through a scatter plot of data points that best expresses the relationship between those points.

Explanation:

what is noncontact force

Answers

Answer:

A non-contact force is a force which acts on an object without coming physically in contact with it.

Explanation:

For example:

Gravitational force.

Magnetic force.

Electrostatics.

Nuclear force.

Answer:

Non-contact force are forces that exist(arise) without any form of contact between two objects.

Examples are ;

: Magnetic Force ;is a force that attracts certain metal objects (like iron and iron filings) towards a magnet. Electrostatic Force ;s the force exerted by a charged body on another charged or uncharged bodyGravitational force ; is a force exerted by the earth on all objects on it

Explanation:

A kettle of water is heated on a stove. What will happen to the molecules of the water in the kettle as the kettle continues to be heated by the flame?

Answers

Answer:

The molecules will take the heat energy and convert it to mechanical energy and they get "excited" and eventually their bonds will break and they will turn into water vapor.

When your body takes the chemical energy in food and transforms it so you can move, what type of energy did it transform it into?

Radiant energy


Chemical energy


Thermal energy


Mechanical energy

Answers

Answer:

chemical I think

Explanation:

hope this helps

Answer:

its actually mechanical energy

Explanation:

i took my quiz

Which statement best describes the size of the outer planets? All the outer planets are large. All the outer planets, except Saturn, are large. The inner planets are larger than the outer planets. Jupiter is a large planet, while the other outer planets are small.

Answers

Answer:

all outer planets are large

Explanation:

The sun and the planets compose the solar system. The common factor among all the outer planets is that they are large.

What are the planets?

The planets constitute an essential part of the solar system. The sun is at the center of the solar system and is surrounded by the planets.

Now the earth is the third planet in the solar system. The outer planets are the planets that are all far from the sun. The common factor among all the outer planets is that they are large.

Learn more about planets: https://brainly.com/question/14581221

Two magnets are placed near each other on a space station orbiting Earth.
Their north poles are facing each other. Which statement explains what will
happen to the magnets?
O A. They will be repelled because they are in each other's magnetic
field.
B. They will not move because they have only half of a magnetic
field.
C. They will not move because they have very small gravitational
fields.
D. They will be attracted because their electric fields will add
together

Answers

Answer: A. They will be repelled because they are in each other's magnetic

field.

Explanation: Apex and gravity and electrical don't have effect on magnets magnetic field.

The statement that described the happening to the magnets should be that they will be attracted because they are in each other's magnetic.

What is a magnet?

Magnet refers to the  piece of iron or other material that comprise of the atoms also it inbuilt the magnetism properties like attraction of other type of iron objects. In the case when the two magnets shoud be placed near to each other also their north poles should be faced each other so it should be attracted since it is considered as the each other magnetic.

Learn more about magnet here: https://brainly.com/question/15122026

In addition to the idea that Jupiter has moons orbiting it, what other evidence did Galileo use to support Copernicus’s model and disprove Aristotle and Ptolemy?

Answers

Galileo's observations of Jupiter's orbiting moons showed that there were other centers of motion in the universe. Galileo's most crucial observation was the observation of Venus in different phases, which directly supported the idea that objects orbit the Sun rather than Earth.

Answer:

Venus has phases similar to the moon’s phases.

Explanation:

i hope this helped you :)

Mrs. Franklin loves teaching science and thinks about it all the time. While walking one day, she steps on a warm, fresh piece of used gum. The gum flattens and sticks to her shoe. When she lifts her foot, she sees long strings of gum between her shoe and the sidewalk. She thinks, “What a great demonstration of the properties of metals!” What properties of metals would Mrs. Franklin most likely teach about with this demonstration?

Answers

Answer:

Ductility and Malleability

Explanation:

A scientist has two containers. Inside each container, there is a blue liquid. The liquids are substances. What can the scientist do to help find out whether these two liquids are both the SAME substance? *

Answers

the scientists can test them both out.

A person is walking from the front of a train toward the back of a train at a constant velocity of 3 mph. The train is moving forward at a velocity of 20 mph. What is the velocity of the walking person relative to the land outside the train?

Answers

Explanation:

This is the Galilean transformation.

V' = V - U   where want to find V' in the primed frame of reference.

The primed frame is moving at speed U = -20 relative to the train.

V = -3 is the speed of the person in the frame of the train.

Then V' = -3 - (-20) = 17 mph relative to the land outside the train.

11. If humans continue to divert water from rivers for crops, drinking and industry, what parts of the water cycle are most affected?
A. Runoff and Accumulation
B. Evaporation and Transpiration
C. Evaporation and Precipitation​

Answers

Is B if is not am sorry

Calculate the average force that must be exerted on a 0.145 kg baseball in order to give it an acceleration of 130 m/s^2. (round to the nearest whole number)

Answers

Answer:

18.9 N or 19 N rounded

Explanation:

m = 0.145 kg

a = 130 m/s^2

F = ma = (0.145 kg)(130 m/s^2) = 18.9 N

Magnitude of the average force

F = 18. 9 N

There are three laws of motion that are  given by  Newton in order to study the Force and Inertia on the objects in motion or rest.

Newton's First Law defines Inertia

The second law gives the definition of Force

Third law states about action reaction pairs on the objects interacting with each other.

According to Newton' s second law of motion we can write equation (1)

[tex]\rm F = ma.....(1) \\\rm Where\; F = Net\; unbalanced\; external\; force\; acting\; on \; the \; system \\\\a = acceleration \; of \; center\; of\; mass\\[/tex]

Now according to the question

we can write

Mass of the baseball = 0.145 kg

Acceleration of the baseball = 130 [tex]m/s^2[/tex]

Magnitude of the average force can be find out by putting in equation (1)

F = ( 0.145 ) ( 130) = 18.85 N [tex]\approx[/tex] 18. 9 N

For more information please refer to  the link below

https://brainly.com/question/19860811

PLEASE ANSWER FAST!!What was significant about the clay samples from the Western Hemisphere? How was the Alvarez hypothesis modified in response?​

Answers

Answer:

The Western Hemisphere contained significantly higher amounts of shock-fractured quartz. This led Walter and Luis Alvarez to hypothesize that the asteroid impact site was in the Western Hemisphere.

Explanation:

TRUE or FALSE? If a moving object experiences an unbalanced force, then the
object will have an acceleration that is in the same direction as the unbalanced
force.

Answers

True I guess

because if the force is balanced and there is no net force, the object will not accelerate and the velocity will remain constant...

Not sure

What is the smallest part of a chemical compound that has all the properties
of that compound
A. A nucleus
B. A mineral
C. An atom
D. A molecule

Answers

Answer:

D. A Molecule

Explanation:

The smallest particle of a compound that still has the properties of the compound is a molecule. It is composed of two or more bonded atoms.

The smallest part of a chemical compound that has all the properties of that compound is a molecule (option d)

In the world of chemistry, substances are composed of tiny units called atoms, and these atoms bond together to form chemical compounds.

Option A, a nucleus, refers to the central core of an atom and consists of protons and neutrons. While essential for an atom, a nucleus alone does not represent a complete chemical compound.

Option B, a mineral, is a naturally occurring inorganic substance with a specific chemical composition and a definite atomic structure. However, minerals are not the smallest parts of a chemical compound.

Option C, an atom, is the fundamental building block of matter. It consists of a nucleus (containing protons and neutrons) surrounded by electrons. While atoms are crucial for forming compounds, they are not the smallest unit that retains all the properties of a compound.

Therefore, the correct answer is Option D, a molecule. A molecule is a group of two or more atoms bonded together, representing the smallest part of a chemical compound that possesses all the characteristics and properties of that compound.

Hence the correct option is (d).

To know more about compound here

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Give two examples of pure substances and two examples of mixtures​

Answers

Answer:

1 kerosene is the pure substance, salt and water is the mixture substance

Answer:

pure substansubdiamond nd sulphur. mixture:salt nd oil ,oil nd water

1. How many energy levels do the electrons in an atom of iron occupy?​

Answers

Electrons in atoms occupy energy levels, also called electron shells, outside the nucleus. Different shells can hold different maximum numbers of electrons. The electrons in an atom occupy the lowest available energy level first.on:

Answer:

26. Brainliest?

Explanation:

Iron atoms have 26 electrons and the shell structure is 2.8.

Difference between si unit and derived unit​

Answers

Answer:

Derived units are derived from these 7 base units. Derived units are dependent on the base units and are not independent of each other. ... Mass has SI units of kg, distance is measured in m and t has the SI unit of second. Thus, SI unit of force is kg.

2. A ball is dropped from a height of 52 m. The ball falls freely and reaches the ground in 75 s. What was the average speed of the ball?​

Answers

Answer:

v = 0.69 m/s

Explanation:

Given that,

A ball is dropped from a height of 52 m.

The ball reaches the ground in 75 seconds

We need to find the average speed of the ball. The ball will travel a distance of 52 m in 75 s. The average speed of the ball is distance divided by time taken. So,

[tex]v=\dfrac{52\ m}{75\ s}\\\\v=0.69\ m/s[/tex]

Hence, the average speed of the ball is 0.69 m/s.

What do the planets have in common and how are they different?

Answers

They are all different sizes and distances from the sun, they all rotate around the sun

Answer:

They vary quite a lot, yet there are some similarities

Explanation:

With Mercury, you have a hot and barren expanse of rock

With Venus, you also have a fairly hot and barren expanse of rock, with a molten core

With Earth, you have a warm/cool variant with water and a full atmosphere

With Mars, you have a colder and barren expanse of valleys and rock, with a rather paste-like ground

With Jupiter, we have our first gas giant, covered in clouds with a thick atmosphere

With Saturn, it is yet another gas giant, with rings of gas and rock and a dense core of metals, such as iron and nickel

With Uranus, it is also rather gas-full with a fair amount of water and methane, which results in its bluish color (an ice giant)

And finally with Neptune, it is the other ice giant, consisting of water, methane, and ammonia

So there are some similarities (gases, water, land formations, etc.) and some differences (rings, temperature, structure, etc.). Our planets are very unique to one another and continue to engage and surprise us.

How to keep your community clean

Answers

Answer:

Work with the local civic groups to identify and eliminate eyesores, and beautify the local environment

Pick up a piece of litter every day

Keep a litter bag in your car or your recreational vehicle so you dispose of litter properly

Create a trash fishing contest in your waterway to increase awareness about illegal dumping and littering

Write a letter to the editor of your local newspaper asking others to respect public lands and keep them clean

Help your local schools conduct recycling drives and clean-up projects

Create a beautiful green space by planting trees and shrubs in an area in need of improvement.

Ask local businesses to adopt-a-spot and take care of it

Paint and fix up playground equipment

Organize a paint-out with family and friends and create a community paintbrush mural over a wall of illegal graffiti

Recycle your old tires

Report graffiti to your local authorities

Donate your old computer equipment or dispose of it properly

Conduct a recycling drive in your neighborhood or your business

Volunteer to help your employer conduct paper recycling drives at work

Donate gently used clothes to needy organizations and shelters and identify other items that you can reuse

Compost yard and food waste and seek advice if you don’t know how

Find out how pollution in storm drain runoff can impact our aquifers and ecosystems and be passionate about doing your part to reduce litter and solid waste

Ask your local government officials to establish regular community improvement activities and to support and promote volunteer efforts

Help your library establish an environmental corner that offers books and other educational materials about taking care of the Earth

Please help me fast and i brainliest!! Two balls are released from the same height. Ball A is released on the surface of Earth, and ball B is released on the surface of the moon. The mass and net force on each ball are recorded in the table. Net Force (N) Mass (kg) Ball A 19.6 2 Ball B 9.6 6 Ball C 6.6 ? Which statement is correct about the mass of ball C, which is released on the surface of the moon from the same height? The mass of ball C is less than the masses of ball A and ball B. The mass of ball C cannot be determined from the information provided. The mass of ball C is greater than the masses of ball A and ball B. The mass of ball C is greater than the mass of ball A but less than the mass of ball B

Answers

Answer:

If they both start at the same height then most likely that means that each has an intical velocity  and a net force sooooo ball A 19.6

Explanation:

Answer: The mass of ball C is greater than the mass of ball A but less than the mass of ball B.

What is the meaning of the universe?

Answers

Answer:

Explanation:

All existing matter and space considered as a whole; the cosmos. The universe is believed to be at least 10 billion light years in diameter and contains a vast number of galaxies; it has been expanding since its creation in the Big Bang about 13 billion years ago.

The universe is all forms of matter and energy, which makes up space, planets, stars and more. The universe is what makes the world go round.

A ball thrown vertically upward is caught by the thrower after 4.00 sec. Find the initial velocity of the ball and the maximum height it reaches.

Answers

Answer:

Initial velocity = 39.2m/s

Maximum height is 78.4m

Explanation:

Given

[tex]Time, t = 4s[/tex]

Solving (a): Initial Velocity

Using first law of motion:

[tex]v = u + at[/tex]

Where

[tex]v = final\ velocity = 0[/tex]

[tex]u = iniital\ velocity = ??[/tex]

[tex]a = acceleration = -g[/tex] [g represents acceleration due to gravity]

[tex]t = 4[/tex]

Substitute these value in the above formula:

[tex]v = u + at[/tex]

[tex]0 = u - g * 4[/tex]

[tex]0 = u - 9.8 * 4[/tex]

Take g as 9.8m/s²

[tex]0 = u - 39.2[/tex]

[tex]u = 39.2m/s\\[/tex]

Hence, initial velocity = 39.2m/s

Solving (b): Maximum Height

This will be solved using second equation of motion

[tex]s = ut + \frac{1}{2}at^2[/tex]

This becomes

[tex]s = ut - \frac{1}{2}gt^2[/tex]

Substitute values for u, t and g

[tex]s = 39.2 * 4 - \frac{1}{2} * 9.8 * 4^2[/tex]

[tex]s = 156.8 - 78.4[/tex]

[tex]s = 78.4[/tex]

Hence, the maximum height is 78.4m

Please answer the questions here in the attachment I attached below. They are all multiple choice.

Answers

Answer:

abcbc

Explanation:

Give two examples of mixtures in which the physical properties of the ingredients, or substance, are maintained, or NOT changed, when they are mixed together

Answers

Answer: Examples are --- Water and oil , nails and sand  and are called Heterogeneous mixtures ,

Explanation:

A mixture is a combination of  two or more substances without a  chemical reaction which individual  components having retain their properties, We have two types of mixtures

Homogeneous-- Is a mixture, whether solid liquid or gas that contains proportions in such a way that one can hardly identify  each components by looking eg --air, ink etc

Heterogeneous- Is a mixture in which the physical properties of individual components are maintained  eg --- Rice and beans , water and oil, nails and sand.

is 45 m/s2 a scalar or a vector quantity and how do you know?

Answers

Answer:

Explanation:

it is a vector as it has a magnitude and a direction. If it was a scalar quantity it would just have a magnitude and would be 45 m. Acceleration is an example of a vector quantity

An airplane flying due north at 90 km/h is being blown due
west at 50 km/h. What is the resultant velocity of the plane?
a
74 km/hr
b 82 km/hr
С
103 km/hr
d 95 km/hr

Answers

Answer:

74km/h

Explanation:

Answer:

103 km/hr

Explanation:

Please Answer: Which lists the waves in order of frequency, from highest to lowest? A.X-rays, gamma rays, ultraviolet B.radio waves, visible light, X-rays C.ultraviolet, microwaves, gamma rays D.visible light, infrared, microwaves

Answers

Answer:

D.visible light, infrared, microwaves

Explanation:

Answer:

visible light, infrared, microwaves

Explanation:

from highest to lowest

A rope is used to pull a 4.0 kg bucket of water upwards out of a deep well with an applied force 45 N. If starting from rest, what speed will the bucket have after experiencing this force for 2 seconds?

Answers

Answer:

v = 22.5 m/s

Explanation:

The speed of the bucket can be found using the following equation:

[tex] V_{f} = V_{0} + at [/tex]

Where:

[tex]V_{f}[/tex]: is the final speed =?

[tex]V_{0}[/tex]: is the initial speed = 0 (starts from rest)

a: is the acceleration

t: is the time = 2 s

We need to find the acceleration, it can be found as follows:

[tex] F = ma [/tex]

Where:

F: is the force = 45 N

m: is the mass = 4.0 kg

[tex] a = \frac{F}{m} = \frac{45 N}{4.0 kg} = 11.25 m/s^{2} [/tex]

Now, the speed is:

[tex] V_{f} = V_{0} + at = 11.25 m/s^{2}*2 s = 22.5 m/s [/tex]

Therefore, the speed that the bucket will have is 22.5 m/s.

I hope it helps you!

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