1 oto chạy trên 1 đoạn đường thẳng từ địa điểm A đến địa điểm B phải mất 1 khoảng thời gian t, Tốc độ của oto trong nửa đầu của khoảng thời gian này là 60km/h và trong nửa cuối là 40km/h. Tính tốc độ trung bình của oto trên cả đoạn đường AB

Answers

Answer 1

Answer:

Explanation:

t = (½d)/60 + (½d)/40

t = (½d)/60(2/2) + (½d)/40(3/3)

t = (½d)2/120 + (½d)3/120

t = (½d)5/120

t = (½d)/24

t = d/48

v = d/t

v = d / (d/48)

v = 48 km/h


Related Questions

pleaseeeeeee help
What happens to light as it moves at an angle into a medium that has a higher index of refraction?
A. It slows down, and the angle decreases.
B. It speeds up, and the angle increases.
C. It slows down, and the angle increases.
D. It speeds up, and the angle decreases.

Answers

I believe it is d I think

As an admirer of Thomas Young, you perform a double-slit experiment in his honor. You set your slits 1.01 mm apart and position your screen 3.09 m from the slits. Although Young had to struggle to achieve a monochromatic light beam of sufficient intensity, you simply turn on a laser with a wavelength of 639 nm . How far on the screen are the first bright fringe and the second dark fringe from the central bright fringe

Answers

Answer:

[tex]0.00195\ \text{m}[/tex]

[tex]0.00293\ \text{m}[/tex]

Explanation:

m = Order = 1

D = Distance between screen and slit = 3.09 m

d = Slit distance = 1.01 mm

[tex]\lambda[/tex] = Wavelength = 639 nm

Distance from the first bright fringe from the central bright fringe is given by

[tex]y=\dfrac{m\lambda D}{d}\\\Rightarrow y=\dfrac{1\times 639\times 10^{-9}\times 3.09}{1.01\times 10^{-3}}\\\Rightarrow y=0.00195\ \text{m}[/tex]

Distance from the first bright fringe from the central bright fringe is [tex]0.00195\ \text{m}[/tex]

Distance from the second dark fringe from the central bright fringe is given by

[tex]y=(m+\dfrac{1}{2})\dfrac{\lambda D}{d}\\\Rightarrow y=(1+\dfrac{1}{2})\dfrac{639\times 10^{-9}\times 3.09}{1.01\times 10^{-3}}\\\Rightarrow y=0.00293\ \text{m}[/tex]

Distance from the second dark fringe from the central bright fringe is [tex]0.00293\ \text{m}[/tex].

What do microwaves have In common with light waves?

Answers

Answer:

Both are electromagnetic waves

Explanation:

Hope this helped!!

Two scientists are experimenting with pure samples of isotope X, a highly radioactive substance. The first scientist has a sample with a mass of 20 grams. He measures a half-life of 232 seconds. The second scientist has a sample of the same substance with a mass of 80 grams. What is the half-life that she is most likely to measure?

Answers

Answer:

Half-life does not depend on sample size, only on the constituents of the sample.

The second scientist should also observe a half-life of about 232 sec or 40 grams of  X remaining after 232 sec.  

Answer:

As it is the same substance, the half life will remain at 232 seconds.

Explanation:

Verified with correct test results.

Which is the correct formula for calculating speed?
A. speed - distance - time
B. speed = distange + time
C. speed = distance - time
D. speed = distance - acceleration

Answers

Answer:

speed=distance/time

Explanation:

its distance over time like division

Water enters a shower head
through a pipe of radius 0.0112 m
at 3.75 m/s. It flows through 25
small holes, each of radius
0.001200 m. At what speed does
water come out of the shower
head? (Don't forget, there are 25
holes, not 1.)
(Unit = m/s)

Answers

Answer:

13.1

Explanation:

thats what i put in for acellus and its right

The drawing shows four sheets of polarizing material, each with its transmission axis oriented differently. Light that is polarized in the vertical direction is incident from the left and has an average intensity of 20 W/m2. Determine the average intensity of the light that emerges on the right in the drawing (a) when sheet A alone is removed, (b) when sheet B alone is removed, (c) when sheet C alone is removed, and (d) when sheet D alone is removed.

Answers

Answer:

Explanation:

At the point when light is vertically polarized is incident on the polarizer whose axes are situated at angle points [tex]\theta _1 , \theta _2 , \theta _3[/tex] the intensity power in the wake of going through all the polarisers is given by the Malus law, applied threefold for every one of the three axes.

[tex]I = I_o \ cos \theta _1 \ cos \theta _2 \ cos \theta _ 3[/tex]

The heading of the direction of the polarization is equivalent to the pivoted axes of the polarizer provided that light is an electromagnetic wave, its course of polarization is therefore controlled by the electric field part.

a)

When sheet A is removed, the transmitted light goes through B, at 30°.

[tex]I = I_o \ cos ^2 \theta _1 \ cos ^2 \theta _2 \ cos^2 \theta _3[/tex]

[tex]I = 20 \ cos ^2 30 \ cos ^2 60 \ cos ^2 30[/tex]

[tex]I = 2.81 \ W/m^2[/tex]

b)

When B is removed, No light passes since the axis of A and the axis of C are perpendicular to each other.

c)

When C is removed, the intensity is indeed zero since the axes are aligned and adjusted at 90° to one another.

[tex]\mathbf{d) \ I - I_o cos^2 (0) cos^2 (30) \ cos^2 (60)}[/tex]

[tex]\mathbf{d = 3.75 \ W/m^2}[/tex]

Lithium was one of the metals studied by the American physicist Robert Millikan in his research on the photoelectric effect. When illuminated with blue light of frequency 6.64 x 10" Hz, the photoelectrons ejected from a lithium surface have a maximum kinetic energy of 0.332 eV. What is the threshold frequency for lithium? For this problem, let the value of Planck's constant, h, be 6.63 x 10J's

Answers

Answer:

 f = 7.9487 10¹³ Hz

Explanation:

The photoelectric effect was correctly explained by Einstein assuming that the radiation is composed of photons, which behave like particles.

           hf = K + Ф

It indicates the frequency and the kinetic energy, let's look for the work function

          Ф = hf - K

let's reduce the magnitudes to the SI system

          K = 0.332 eV (1.6 10⁻¹⁹ J / 1 eV) = 0.5312 10⁻⁻¹⁹ J

let's calculate

          Ф = 6.63 10⁻⁻³⁴  6.64 10¹¹ - 0.5312 10⁻¹⁹

          Ф = 4.40 10⁻²² - 0.5312 10⁻¹⁹

          Ф = 5.27 10⁻²⁰ J

for the minimum frequency that produces photoelectrons, the kinetic energy is zero

           hf = Ф  

           f = Ф / h

           f = 5.27 10⁻²⁰ / 6.63 10⁻³⁴

           f = 7.9487 10¹³ Hz

the speed of light in a certain medium is 0.6c. find critical angle , if the index of refraction is 1.67​

Answers

Answer:

[tex]\theta_c = 36.78^o[/tex]

Explanation:

The relationship between the refractive index and the critical angle is given as follows:

[tex]\eta = \frac{1}{Sin\ \theta_c} \\\\Sin\ \theta_c = \frac{1}{\eta}\\\\\theta_c = Sin^{-1}(\frac{1}{\eta} )[/tex]

where,

η = refractive index = 1.67

θc = critical angle =?

Therefore,

[tex]\theta_c = Sin^{-1}(\frac{1}{1.67} )[/tex]

[tex]\theta_c = 36.78^o[/tex]

What is the mass of a jet that accelerates at 4 m/s2 after a 4,000 N force from the engines?

Answers

Answer:

1000kg

Explanation:

F=MA

Rearrange the formula: M=F/A

plug in values for F (force), and A (acceleration).

M=4000/4

M=1000kg

i think.

not sure tho.

The mass of the jet that accelerates at 4 m/s^2 after a 4000 N force from the engines is 1000 kg.

What is Newton's second law of motion?

Newton's second law of motion states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. Mathematically, the law can be expressed as F = ma, where F is the net force acting on the object, m is its mass, and a is its acceleration. This law is fundamental to the understanding of the motion of objects under the influence of external forces.

Rearranging the formula to solve for mass, we get:

m = F / a

Substituting the given values, we get:

[tex]m = 4000 N / 4 m/s^2[/tex]

m = 1000 kg

Therefore, the mass of the jet that accelerates at 4 m/s^2 after a 4000 N force from the engines is 1000 kg.

Learn more about Newton's second law of motion, here:

https://brainly.com/question/13447525?referrer=searchRes

#SPJ3


Find the Net Force on a truck with a mass of 1,500kg and an acceleration
of 10m/s2?

Answers

Answer:

15,000 N

Explanation:

F = ma = (1,500 kg)(10 m/s^2) = 15,000 N

Read each example and identify whether the data are observations or inferences from observations. The fish’s ventral fin measured 8.5 cm long.

Answers

8.5 cm long just bc we love this

Answer:

Observation

Inference

Inference

Observation

Inference

Explanation:

Does gravity increase or decrease with greater mass???

Answers

Answer:

Increase

As the mass of either object increases, the force of gravitational attraction between them also increases.

Explanation:

The gravitational force is directly proportional to the mass of both interacting objects, more massive objects will attract each other with a greater gravitational force.

As the mass of either object increases, the force of gravitational attraction between them also increases.

Answered by none other than the ONE & ONLY #QUEEN herself aka #DRIPPQUEENMO

HOPE THIS HELPED!!!

After the initial experiment, students wondered how a person's weight would influence the results. They conducted a second experiment to determine if the mass of an object affected friction, assuming the types of surfaces remained constant. A spring scale was attached to a wooden block (1 kg). The block was placed on a wooden board and the spring scale was used to pull the block. The magnitude of the force required to start the block moving was recorded in the data table. The experiment was repeated using two, three, and four blocks. The data can be seen in the data table at the top of the page. What is the relationship between static friction and weight?

Answers

Answer:

The greater the weight of the person, the more static friction.

Explanation:

USATestPrep

In this image of an atom, what does the outer area consisting of tiny blue
dots represent?
O A. The electron cloud
B. Protons
C. The nucleus
D. Neutrons

Answers

A- the electron cloud

the ice and steam point on a thermometer are found to be 96ml apart. what temperature is recorded when the length of mercury thread is 33.6ml above the ice point

Answers

Answer:

33.6 / 96   is the fraction of the temperature between ice and freezing

33.6 / 96 = .35

So C = .35 * 100 = 35 deg C  where the ice point would be 0 deg C

You can convert C to F

F = 9 / 5 * C + 32 = 9/5 * 35 + 32 = 95 deg F

What should you do after obtaining a numerical answer when solving a problem?

Answers

I think you’re supposed to solve it? Wheres the question

If velocity decreases what happens to acceleration

Answers

Answer: Velocity is a vector; the word decreasing only applies to its magnitude (not its direction) which is called speed. If speed is increasing and direction is not changing, then acceleration is positive. If speed is constant then acceleration is zero. If speed is decreasing then acceleration is negative.

Explanation:

What is the gravitational potential energy of a 4 kg bowling ball 1 m above the ground?

Answers

Answer:

40 J

Explanation:

Gpe= mgh

=4*10*1

=40

Families attempting to rebound from crises are advised to discontinue family rituals and leisure activities, as they may regenerate negative family stress and threaten resilience.

A. False
B. True

Answers

The answer is B. Yes I know it’s correct .

what is the planet that scientists are exploring now?​

Answers

Answer:

Mars

Explanation:

In the 1960s, humans set out to discover what the red planet has to teach us. Now, NASA is hoping to land the first humans on Mars by the 2030s. Mars has captivated humans since we first set eyes on it as a star-like object in the night sky.

good luck

please mark me as a brainliest

What is meant by the terms critical mass and supercritical?

Answers

Answer:

Critical mass is the minimum mass of fissionable material required to sustain a nuclear fission reaction, and a supercritical mass, which will provide more than enough neutrons to sustain a fission reaction at the time of detonation.

Explanation:

How efficient are the small and large scale solar-power systems used in individual homes and industrial settings? What is the environmental impact of the generation of solar power?

In detail plz

Answers

Answer:

[tex]\color{Blue}\huge\boxed{Answer} [/tex]

The potential environmental impacts associated with solar power—land use and habitat loss, water use, and the use of hazardous materials in manufacturing—can vary greatly depending on the technology, which includes two broad categories: photovoltaic (PV) solar cells or concentrating solar thermal plants (CSP).

Explanation:

I just answer the second question


A student pushes a 12 N book to the
right with a force of 10 N. The book
experiences a frictional force of 3 N.

Answers

Answer:

Explanation:

My name is Jeff

In free fall, where does an object have the slowest speed? *
O Vi
O vf
Vtop
O more than one is correct

Answers

Answer:

vi and vtop = 0

Explanation:

Free fall is a motion of a body in which the only force acting of the body is the Gravitational Force. In this motion body moves with constant acceleration i.e acceleration due to gravity.

When an object is thrown downward from a non zero height say h the motion is referred to as free fall with initial velocity of object beign zero. Hence v=0

In free fall, an object have the slowest speed at the beginning of the motion which is at the top before the object starts to fall. [tex](V_i \ and \ V_{top})[/tex]

During a free fall, the object subjected to only acceleration due to gravity. The velocity of object increases as the object moves downwards and eventually becomes maximum before the object hits the ground.

The final velocity of the object is the greatest while the initial velocity of the object at the top before the free fall is the slowest.

[tex]V_f > V_i \ or\ V_{top}[/tex]

Thus, we can conclude that during a free fall, the velocity of the object increases downwards. The slowest speed can found at the beginning of the motion.

Learn more here:https://brainly.com/question/11698474

1. What is transferred from place to place by waves?

Answers

Answer:

Energy

Explanation:

A wave is a disturbance that transfers energy from one place to another without transferring matter. Waves transfer energy away from the source, or starting place, of the energy.

What structure is represented by the letter C?
PLEASE HELP!!!!!!!!!!!!!
Choose 1 answer:
A) Lysosome
B) Nucleus
C) Vacuole
D) Mitochondria

Answers

Answer:

The picture is blacked out.

Answer:

If I'm correct the answer would be A) Lysosome.

The attachment is black so I can't promise you that it's the one you're looking for. But I did it on khan

If the radius of the Earth is 6400.0 km and the atmosphere is 10.0 km high, then the volume of air around the Earth is what? ​

Answers

Answer:

5.16 x 10^18 m^3

Explanation:

Two out-of-tune flutes play the same note. One produces a tone that has a frequency of 246 Hz, while the other produces 289 Hz. When a tuning fork is sounded together with the 246-Hz tone, a beat frequency of 18.0 Hz is produced. When the same tuning fork is sounded together with the 289-Hz tone, a beat frequency of 25.0 Hz is produced. What is the frequency of the tuning fork

Answers

Answer:

[tex]264\ \text{Hz}[/tex]

Explanation:

Beat frequency of the first case = 18 Hz

Beat frequency of the second case = 25 Hz

Tone of first fork = 246 Hz

Tone of second fork = 289 Hz

First case

Beat frequency is given by

[tex]\Delta f=|f_2-f_1|\\\Rightarrow f_1=246\pm18\\\Rightarrow f_1=264, 228\ \text{Hz}[/tex]

Second case

[tex]f_2=289\pm 25\\\Rightarrow f_2=264, 314\ \text{Hz}[/tex]

The frequency of the tuning fork is [tex]264\ \text{Hz}[/tex].

A piece of wood that floats on water has a mass of 0.0175 kg. A lead sinker is tied to the wood, and the apparent mass with the wood in air and the lead sinker submerged in water is 0.0765 kg. The apparent mass with both the wood and the sinker both submerged in water is 0.0452 kg. What is the SG of the wood

Answers

Answer:

The specific gravity of the wood is 1.56

Explanation:

Given;

mass of the wood in water, [tex]M_w_{H_2O}[/tex] = 0.0175 kg

apparent mass of the wood and lead sinker submerged in water, [tex]M_w_{(air)} + M_s_{H_2O}[/tex] = 0.0765 kg

apparent mass with both the wood and the sinker both submerged in water, [tex]M_w_{H_2O} + M_s_{H_2O} = 0.0452 \ kg[/tex]

Mass of the lead sinker alone submerged in water;

[tex]M_w_{H_2O} + M_s_{H_2O} = 0.0452 \ kg\\\\0.0175 \ kg + M_s_{H_2O} = 0.0452 \ kg\\\\M_s_{H_2O} = 0.0452 \ kg - 0.0175 \ kg\\\\M_s_{H_2O} = 0.0277 \ kg[/tex]

Mass of the wood in the air;

[tex]M_w_{(air)} + M_s_{H_2O} = 0.0765 \ kg\\\\M_w_{(air)} + 0.0277 \ kg = 0.0765 \ kg\\\\M_w_{(air)} = 0.0765 \ kg - 0.0277 \ kg\\\\M_w_{(air)} = 0.0488 \ kg[/tex]

Mass of water is calculated as follows;

[tex]M_w_{(air)} - M_w_{H_2O} = M_{H_2O}\\\\0.0488 \ kg - 0.0175 \ kg = M_{H_2O}\\\\0.0313 \ kg = M_{H_2O}[/tex]

The specific gravity of the wood is calculated as follows;

[tex]Specific \ gravity\ (S.G) \ of \ wood = \frac{mass \ of \ wood\ in \ air }{mass \ of \ water} \\\\Specific \ gravity\ (S.G) \ of \ wood = \frac{0.0488}{0.0313} \\\\Specific \ gravity\ (S.G) \ of \ wood = 1.559 = 1.56[/tex]

Therefore, the specific gravity of the wood is 1.56

Other Questions
If three bakers can prepare 15cakes in 60 minutes, if theycontinue working at the samerate, how many cakes can theymake in 3 hours? Simon wants to earn as many points as possible in one turn in a game. Two number cubes whose sides are numbered 1 through 6 are rolled. He is given two options for the manner in which points are awarded in the turn.OPTION A: If the sum of the rolls is a prime number, Simon receives 15 points.OPTION B: If the sum of the rolls is a multiple of 3, Simon receives 12 points.Which statement best explains the option he should choose?A. Simon should choose Option B. The mathematical expectation of this option is 6.25 and is the greater mathematical expectation of the two options.B. Simon should choose Option A. The mathematical expectation of this option is 6.25 and is the greater mathematical expectation of the two options.C. Simon should choose Option B. The mathematical expectation of this option is 4 and is the greater mathematical expectation of the two options.D. Simon should choose Option A. The mathematical expectation of this option is 4 and is the greater mathematical expectation of the two options. Chlorophyll is essential to photosynthesis because it traps the _______________ needed. A. oxygen B. carbon dioxide C. sunlight D. water two companies working together can clear a parcel of land in 9 hours. working alone,it would take company A 3 hours longer to clear the land than it would company B. How long would it take company B to clear the parcel of land alone ( round your answer to the nearest tenth.) BRAINLESplz help thank you Two numbers have a sum of - 6 and a product of 9.Use the quadratic equation n^2 - 6n + 9 = 0 to determine the two numbers. n2 - 6n + 9 = 0 At a restaurant your family spends $45.00 on lunch. If they want to leave a 15%tip, How much should they leave as a tip for the waitress?$67.50$6.75$4.50 What is the Taj Mahal? Explain who had it built and for what purpose. Help ASAP Ill mark you as brainlister The _____ is important to the cultural context of Nectar in a Sieve. Select all that apply. 1.A sample of gas in a closed container occupies 250. mL at 1.25 atm of pressure. If the pressure increases to 2.00 atm while the temperature stays the same, what is the new volume in mL?2.A sample of gas is held inside a flexible container where pressure is kept constant. At room temperature (21.1C), the container has a volume of 1.50 L. What is the volume of the gas if the container is placed in a deep freezer at -10.0C?3.A sample gas is held inside a rigid container with a pressure of 50. kPa and a temperature of 290 K. What is the new temperature of the gas if the pressure is doubled? If x^2 4x + 4 = 49, then what is x Based on the data given in the table,which is a reasonable estimate ofthe download time of a 600-kilobyteA 10 secondsB 12 secondsC 15 secondsD 17 seconds Explain how humans are able to produce one type of hemoglobin as they develop in utero, then produce another to use after birth I will give brainliest. And don't leave a link to some file.In 46, Monique rolls a six-sided number cube labeled 1 to 6. 4. Find P(rolling a 4). 5. Find P(rolling an odd number). 6. If Monique rolls the number cube 12 times, how many times would she expect a number greater than 4 to be rolled? What is the value of the expression?5/12+7/34 GIVING BRAINLIEST PLEASE HELP!!-if you answer correctly ill give you brainliest which will give you 23pts- During the last few months, Maria has seen deer in her backyard on 13 days and no deer on 52 days. What is the approximate probability that she will see deer in her yard tomorrow?A. 33.3%B. C. 0.25D. pls pls pls, I beg you to answer this question only if you know the correct answer please please please I beg you of the students in the lunch room 40% are girls there are 20 girls in the the lunch room how many students are in the lunch room