A car is moving at a speed of 72 km / h on a horizontal section. What is the braking distance of the car if the friction force is equal to the size of the weight of the car? (20 m) (+ formula)

Answers

Answer 1

Answer:

20.4m

Explanation:

72kmhr(1000mkm)(hr3600sec)=20ms  

Use principles of conservation of energy.

The initial kinetic energy of the car is equal to the work done by friction during braking:

KE=Wfric  

12mv2=(Ffric)d  

but the force of friction = weight of the car = mg

12mv2=mgd  

mass cancels in both terms, which tells us the answer is independent of mass

12v2=gd  

12202=(9.81)d  

d=20.4m  

Note that the correct answer should actually be 20. m with only 2 significant figure accuracy since 72 km/hr only has 2 sig fig accuracy.


Related Questions

Menciona tres diferencias entre un planeta y un satélite natural.

Answers

Answer:

1. Un planeta gira alrededor del Sol mientras que un satélite  gira alrededor de un planeta.

2. Tamaño

3. Aspectos Físicos

4. Creación

A source produces 25 waves every second. The wavelength of the waves is
50 cm. How fast will the waves be travelling?

Answers

Answer:  

1 s

Explanation:

The speed of the sound, distance travelled and the time taken relationship is given as follows.

Speedofsound,v=Distancetravelled×Timetaken ----eqn 1

With the given values of wavelength = 50 cm = 0.5 m and frequency =1000 Hz, the speed of the wave is calculated as follows.

Speedofsound,v=Frequency(ν)×Wavelength(λ) -- eqn 2

That is, v=ν×λ=1000Hz×0.5m=500m/s

Substituting the value of the speed of sound in eqn 1 gives the time taken for the sound wave to travel a distance of 500 m.

That is, Timetaken=

Distancetravelled

Speedofsound

=

500m

500m/s

=1second.

Hence, the time taken for the sound wave to travel is 1 second.

The speed with which the waves will be travelling is 12.5m/s.

Given the data in the question;

Frequency; [tex]f = 25\ waves\ per\ second = 25s^{-1}[/tex]Wavelength; [tex]\lambda = 50cm = 0.5m[/tex]

Speed of the wave; [tex]v =\ ?[/tex]

To determine how fast the waves will be travelling, we use the expression for the relations between wavelength, frequency and speed of wave.

[tex]\lambda = \frac{v}{f}[/tex]

Where [tex]\lambda[/tex] is wavelength, f is frequency and v is speed of wave

We substitute our values into the equation

[tex]0.5m = \frac{v}{25s^{-1}} \\\\v = 0.5m * 25s^{-1}\\\\v = 12.5ms^{-1}[/tex]

Therefore, the speed with which the waves will be travelling is 12.5m/s.

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Select two of Earth's spheres and explain how they interact with each other.
atmosphere, biosphere, cryosphere, geosphere and hydrosphere
HELPPPPPPPP!!!!!

Answers

Answer and Explanation: The geosphere interacts with the cryosphere when glaciers and sheets of ice from the cryosphere erode the rocks located on the geosphere. This happens as ice passes over the land and carries eroded rocks to new locations. The cryosphere can also cause soil to become icy and take hold of greenhouse gases from the atmosphere. The geosphere is the part of the Earth that has rocks, minerals, sand, and lava. The cryosphere has frozen water, ice, and glaciers. The cryosphere also interacts frequently with the hydrosphere because it draws water from the hydrosphere and freezes it during cold temperatures. Warmer temperatures cause the cryosphere to melt and release water back to the hydrosphere.

solve for the BMI weight 58kg Height 1.61​

Answers

Answer:

Explanation:

BMI= weight/(height × height)          ; weight in kilogram and height in metter

     = 58kg / (1.61m  × 1.61m )

     = (58/ 2.5921) kg/[tex]m^{2}[/tex]

     = 22.375  kg/[tex]m^{2}[/tex]

     ≈ 22.4 kg/[tex]m^{2}[/tex]

The part of the shore that represents the water's edge and migrates back and forth with the tide is known as the ________.

Answers

Answer :It is know as the shore line

Explanation:

Question 5: A heavy rope is flicked upwards, creating a single pulse in the rope. Make a drawing of the rope and indicate the following in your drawing
a. the direction of motion of the pulse
b. Amplitude
c. Pulse length
d. Position of the rest​

Answers

Answer:

the direction of motion of the pulse

if there is a gravitational force between all objects, why do we not feel or observe it?

Answers

We do not feel the gravitational forces from objects other than the Earth because they are weak.

Answer:

We do. It's just way too small compared to the force between the objects we're observing and the earth. It's like looking inside a room with an elephant and a grain of rice. The rice is there, it's just too small compared to the room and the elephant inside for you to notice it. Or, if you ever traveled on a plane, you can easily see the towns, or the roads, but not the single people walking the street.

the ground wire on a household circuit is typically what color

Answers

Answer:

Hey mate....

Explanation:

This is ur answer.....

Green & Yellow

Hope it helps!

Brainliest pls!

Follow me! :)

The ground wire on a household circuit is green in color in a typical household

What is an electric charge?

Charged material experiences a force when it is subjected to an electromagnetic field due to the physical property of electric charge. You can have positive or negative electric charges (commonly carried by protons and electrons respectively). opposing charges attract one another whereas similar charges repel one another. We refer to an object as neutral if it has no net charge.

The charge on one electron is -1.6 ×10⁻¹⁹ coulomb.

The ground wire is either bare or has green insulation in most residential branch circuit cables in the US.

The norm in Europe and the UK is

live, brown

neutral is blue.

stripes with green and yellow: earth.

Thus,the ground wire on a household circuit is green in color in a typical household

Learn more about an electric charge from here

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it is not 132m and plzz explain how the answer is 66m​

Answers

Distance = 1/2 x velocity x time

Distance = 1/2 x 0.40 x 330

Distance = 66 meters

A student has fallen behind on her homework and suddenly realizes that a big research paper is due the next day and she has not even started working on it. She panics, staying up all night to write her paper, but still runs out of time. At the last minute, she finds a research paper online that covers the same topic as her paper, and she copies and pastes large portions of text from the website into her paper. The student’s behavior is an example of what? a violation of intellectual property rights an online invasion of privacy inappropriate use of Internet sites an incident of cyberbullying

Answers

Answer:

Violation of intellectual property rights

Explanation:

Im sorry I am late but for the future people its A! :)) Have a great day :)

An element with a force of 0.00SN moves at a minimum: 0.2m / s². Calculate the mass of that element.

Answers

Please find attached photograph for your answer.

Hope it helps.

Do comment if you have any query.

Arthur (mass 79 kg) and Violet (mass 50 kg) are trying to play on a seesaw. If Violet sits 4 m from the fulcrum, at what distance from the fulcrum should Arthur sit

Answers

Hi there!

There are two torques acting on the system:

τ (Arthur) = RW = R(790N)

τ (Violet) = RW = 4(500N) = 2000N

∑τ = 0 = τ(Violet) - τ(Arthur)

Thus:

τ(Violet) = τ(Arthur)

2000 = 790R

R ≈ 2.53m

unlike other kinds or muscle cells, ____muscle cells are able to contract by themselves

A. epithelial
B. Liver
C. Intestinal
D. cardiac

Answers

Answer:

cardiac

Explanation:

cardiac muscle can contact themselves

the second law of thermodynamics imposes what limit on the efficiency of a heat engine?

Answers

A heat engine cannot have a thermal efficiency of 100% For all reversible processes, the second-law efficiency is 100%. The second-law efficiency of a heat engine cannot be greater than its thermal efficiency. The second-law efficiency of a process is 100% if no entropy is generated during that process

the following can increase the amount of friction in the surface, except ______.
a. glue
b. paper
c. lubricant
d. foil​

Answers

Answer:

c. lubricant..........

Hi can u help me in my physics homework

Answers

Answer:

a.) [tex]5 seconds[/tex]

b.) [tex]9.5 m/s[/tex]

Explanation:

Solution is attached.

If a person is pushing a cart with a force of 40 Newtons and it
accelerates at 0.5 m/s², what is the mass of the cart?

Answers

Answer:

80kg

Explanation:

A = Fm

0.5 = 40m

m = 40/0.5

m = 80kg

Nbel! You’re okay! What happened to you?

Answers

Answer:

Wanna be frie nds?

Explanation:

Im smort big brain

Answer:

hello wanna be fr iends and cha-t?

Explanation:

2. In a race, if a runner starts and stops at the same position, what is their
displacement? *

Answers

Answer:

It is the same

Explanation:

I Jsut know



How much potential energy did the the milkshake have after it fell off of the counter, just before it hit the ground (at the bottom)? Make sure to write the correct units with

your answer!

Answers

Answer:

The formula for potential energy depends on the force acting on the two objects. For the gravitational force the formula is P.E. = mgh, where m is the mass in kilograms, g is the acceleration due to gravity (9.8 m / s2 at the surface of the earth) and h is the height in meters.

help please please please please​

Answers

Answer:

lol can u tell what to help u with. cause I didn't understood

If the velocity is 50 and the time is 5 seconds what is the acceleration?

Answers

Just divide the both, you will get the answer!

does it sound rude?

im sorry for that!

Answer:

10

Explanation:


4. According to Newton's First Law of Motion, an object with a net force acting on it will

Answers

Answer:

a object with net force on it will stay in motion unless acted on by an equal opposite force.

stay in motion unless acted on with another object in motion

Find the gravitational potential energy of a body of mass 25kg,kept at a height of 4m If g=10m/s'.

Answers

Answer:

Explanation:E=mgh=25×4×10=1000J

1 =
Q=240c
t=300s

Please explain Im so confused

Answers

Answer:

Answer:

0.8 A

Explanation:

Given: Q = 240 C

t = 300 s

Required: I

Equation: I = Q / t

Solution: I = 240 C / 300 s

Answer: I = 0.8 A

when the acceleration of a block in simple harmonic motion on a spring is zero, what other quantity is also zero?

Answers

Hi there!

When the acceleration of a block in SHM is 0 m/s², the NET FORCE must equal 0 N.

0 m/s² acceleration is obtained when the spring is at its equilibrium point, meaning that:

∑F = -kx (x = displacement from equilibrium point in meters)

If the block is at the equilibrium point, displacement = 0m, so:

∑F = -k(0) = 0 N

With Newton's Second Law, ∑F = ma. If the net force is 0 N, then there is no acceleration experienced by the block.

Thus, the other quantity that must be 0 is the block's NET FORCE.

The gravitational field strength on Mars is 3. 7 N/kg. Kai has a mass of 55 kg. What would Kai weigh on Mars? Give your answer to 1 decimal place.

Answers

Hi there!

Weight = mass × acceleration due to gravity (or gravitational field strength)

We can write this as:

W = mg

Plug in the given values:

W = 55 × 3.7

W = 203.5 N

DESPERATE!! WILL GIVE BARINLIST AND THANKS
Many farmers harvest their crops in the fall and then let the leftover plant material stay on the ground over winter. How does this help prevent erosion?

Answers

Answer:

it grabs unto soil and keeps it clamped together it prevents this makes the soil harder to wash away

Answer:

When the leftovers are left in the autumn, they have two purposes:

- Preventing erosion; the roots remain in the ground, so they hold it tightly till the next planting of the crops.

- Fertilizing the soil with natural material; the roots will not rot quickly in the colder period of the year, but will start rotting much faster in the spring, thus they will enrich the soil.

SHORT ANSWER
Which of the balanced chemical equations below has a molar ratio
with the smallest difference between elemental sodium (Na) as a reac-
tant and the chemical formed as a product? Explain.
Use at least two sentences in your answer.
Word Count: (minimum - 10; maximum - 300)
a. 2Na + F2 = 2 NaF
b. 3Na + P = Na3P
c. Na + N2 2Na N
d. Na + 0 = 2 Na o

Answers

Answer:

A

Explanation:

the formula ,

From the given chemical equations,the one with molar ratio with smallest difference between elemental sodium (Na) as a reactant and the chemical formed as a product is equation 'a'.

What is chemical equation?

Chemical equation is a symbolic representation of a chemical reaction which is written in the form of symbols and chemical formulas.The reactants are present on the left hand side while the products are present on the right hand side.

A plus sign is present between reactants and products if they are more than one in any case and an arrow is present pointing towards the product side which indicates the direction of the reaction .There are coefficients present next to the chemical symbols and formulas .

The first chemical equation was put forth by Jean Beguin in 1615.By making use of chemical equations the direction of reaction ,state of reactants and products can be stated. In the chemical equations even the temperature to be maintained and catalyst can be mentioned.

Learn more about chemical equation,here:

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v=VyV67.2 -8.2 m/s
Part B
Now let's see if your prediction agrees with the experimental results. There isn't any data at y=-3.5 m, so you'll need to interpolate by zooming in
on the relationship between y velocity (W) and y displacement. You'll use Tracker's Data tool to help with this analysis. Follow these steps:
• Change the vy versus t graph to a vy versus y graph. (Click the t label on the horizontal axis and select y. position y-component from the
menu.)
• It's a little hard to see what's going on with this graph at y = -3.5, so zoom in. Double-click on the graph to open it up in the Data tool.
. Put your cursor on the point where the graph line intersects y = -3.5. Click and hold to read the vy at that point shown in a yellow box in the
bottom left comer).
What's the interpolated graph value of v, at y = -3.57 Comment on how well this value agrees with the value of v, that you calculated in part A of
this activity. Make a hypothesis about any notable difference.

Answers

Answer:

-3.5

Explanation:

b/c the distance is moving in to two A And B A +B or S1 +S2 that is it

Answer:

The interpolated velocity value from the graph is -8.1 meters/second. The calculated value based on the average acceleration is -8.2 meters/second. This is very good agreement.

Explanation:

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