Một người đi xe ô tô từ a đến b cách nhau 90km trong nửa quãng đường đầu người dó đi với vận tốc v1 trong nửa quãng đường sau người đó đi với vận tốc v2=2v1/3.Tính vận tốc của người đó trên mỗi chặng đường để sau 1.5h người đó đi đến b

Answers

Answer 1

Answer:

The speed of the first half is 75 km/h and for the second half is 50 km/h.

Explanation:

A person driving a car from a to b 90km apart for the first half of the distance travels with speed v1 the second half of the distance travels with a speed of v2=2v1/3. Calculate his speed per each the distance so that after 1.5 hours that person reaches b

Total distance, D = 90 km

Let the time for he first half is t and for the second half is t'.

Distance = speed x time

45 = v1 x t .... (1)

And

45 = v2 x t' .... (2)

Total time is T = t + t'

[tex]1.5 = \frac{45}{v_1}+\frac{45}{v_2}\\\\1.5 = \frac{45}{v_1}+\frac{3\times 45}{2v_1}\\\\1.5 = \frac{90+135}{2v_1}\\\\3v_1 = 225 \\\\v_1 = 75 km/h[/tex]

Now, v2 = 2 x 75/3 = 50 km/h


Related Questions

A system consisting of two particles is known to have zero total momentum. Does it follow that the kinetic energy of the system is zero as well?

Answers

Answer:

all of the particles are at rest (v = 0)

Explanation:

Therefore, since nothing is moving, the total momentum of the system must also be zero.

As a system consisting of two particles is known to have zero total momentum, the kinetic energy of the system will be zero as well.

What is momentum?

Momentum is the product of a particle's mass and velocity. Momentum is a vector quantity, which means it has a magnitude as well as a direction.

According to Isaac Newton's second law of motion, the time rate of change of momentum equals the force acting on the particle.

Momentum describes the relationship between an object's mass, velocity, and direction.

Any change in momentum generates force. As a result, a change in momentum is used to calculate the force acting on the object.

Because the total kinetic energy is zero, all of the particles are at rest (v = 0). As a result, because nothing is moving, the system's total momentum must also be zero.

Thus, the statement is true.

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A neutral object has:

a. Zero electrons.
b. Zero protons.
c. Only neutrons.
d. An attraction to negative objects.
e. An attraction to neutral objects.

Answers

Answer:

c. Only neutrons.

hope it helps :)

the image in figure 16.36 combines observations made with visible light and radio telescopes. which color in the image represents the radio emission?

Answers

Answer: pinkish- white

Purple

Explanation:

Do I look good yes or no

Answers

Answer:

0/10

Explanation:

_--------------------

Answer:

No. -infinity/10

Explanation:

Ew. Just why, like no.

A bicycle accelerates from rest to 6m/s in a distance of 50m, calculate the acceleration

Answers

50x6=300 this is the answer I think

The acceleration of the bicycle is 0.12 m/[tex]s^{2}[/tex].

We know that acceleration is the change in velocity divided by the change in time. In this case, the bicycle is accelerating from rest to a velocity of 6 m/s. The change in time is the time it takes the bicycle to travel 50 m.

We can use the following equation to find the acceleration:

a = (v2 - v1) / t

where:

a is the acceleration

v2 is the final velocity (6 m/s)

v1 is the initial velocity (0 m/s)

t is the time

Plugging in the values from the problem, we get:

a = (6 m/s - 0 m/s) / 50 s

= 0.12 m/[tex]s^{2}[/tex].

Therefore, the acceleration of the bicycle is 0.12 m/[tex]s^{2}[/tex].

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Mass can be measured with a triple
beam balance in units of
Resources
A. grams
B. Newtons
C. cubic centimeters
D. millimeters

Answers

Answer:

It can be measure by grams

Galois drove 60.0 kilometers due west in 5.00 hours and then drove 43.0 kilometers due north in 3.00 hours.
(a) How far did he travel?
(b) What was his average speed?
(c) What was his displacement?
(d) What was his average velocity?

Answers

Answer:

Explanation:

See the attachment for the details.  A right triangle is formed to find the hypotenuse of the two legs consisting of the actual driving distances and times.  The hypotenuse gives the vector information for the displacement at the end of 8 hours of driving.  

The individual driving times and distances are summed to provide:

(a) How far did he travel?

103 km

(b) What was his average speed?

12.88 km/h

(c) What was his displacement?

73.82 km

(d) What was his average velocity?

9.228 km/h

This property of waves is the only property where the relationship between energy and this property are indirect or inverse

Answers

Answer: I don't understand

Explanation:

study and pay attention



Got a question ~ can someone help me out ?

I want Explanation ~ [ cuz there's something I'm not clear about in this question ]

Thanks for Answering ~

Answers

Answer:

Hey Tyere!

Refer to the attachments....

I hope it is helpful to you...Cheers!____________

The magnitude, M, of an earthquake is represented by the equation M=23logEE0 where E is the amount of energy released by the earthquake in joules and E0=104. 4 is the assigned minimal measure released by an earthquake. In scientific notation rounded to the nearest tenth, what is the amount of energy released by an earthquake with a magnitude of 5. 5?.

Answers

An earthquake with a magnitude of 5.5 releases 4.5 × 10¹² J of energy.

What is the magnitude of an earthquake?

The magnitude of an earthquake is a number that characterizes the relative size of an earthquake and is based on the measurement of the maximum motion recorded by a seismograph.

If the magnitude of the earthquake is M = 5.5, we can calculate the amount of energy released (E) using the following expression.

[tex]M = \frac{2}{3} log(\frac{E}{E_0} )\\\\E = E_0 \times 10^{\frac{3}{2}M } = 10^{4.4} \times 10^{\frac{3}{2}(5.5) } = 4.5 \times 10^{12} J[/tex]

where,

E₀ is the assigned minimal measure released by an earthquake.

An earthquake with a magnitude of 5.5 releases 4.5 × 10¹² J of energy.

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scientific notation. jst 11a

Answers

Answer:

2 * 10^4

Explanation:

(3 * 10^4)(4 * 10^4) / (6 * 10^4)

= (12 * 10^8)/(6 * 10^4)

= 2 * 10^4

Give proof that mass is constant and weight keeps changing.​

Answers


The mass of an object stays the same wherever it is, but its weight can change. This happens if the object goes where the gravitational field strength is different from the gravitational field strength on Earth, such as into space or another planet.

Two 3.0g bullets are fired with speeds of 40.0 m/s
and 80.0 m/s, respectively. What are their kinetic
energies? Which bullet has more kinetic energy? What is the ratio of their kinetic energies?

Answers

Two 3.0g bullets are fired with speeds of 40.0 m/s and 80.0 m/s, respectively. Mass of the 1st bullet (m1) = 3 g = 0.003 KgMass of the 2nd bullet (m2) = 3 g = 0.003 KgVelocity of the 1st bullet (v1) = 40 m/sVelocity of the 2nd bullet (v2) = 80 m/sWe know, kinetic energy of a body

[tex] = \sf \frac{1}{2} m {v}^{2} [/tex]

Kinetic energy of the 1st bullet [tex] \sf = \frac{1}{2} \times m1 \times {(v1)}^{2} \\ \sf= \frac{1}{2} \times 0.003 \times {(40)}^{2}J \\ \sf = \frac{1}{2} \times 0.003 \times 1600J \\ \sf = 2.4J[/tex]Kinetic energy of the 2nd bullet [tex] \sf = \frac{1}{2} \times m2 \times {(v2)}^{2} \\ \sf= \frac{1}{2} \times 0.003 \times {(80)}^{2}J \\ \sf = \frac{1}{2} \times 0.003 \times 6400J \\ \sf = 9.6J[/tex] So, the 2nd bullet which has greater velocity has more kinetic energy.Therefore, the ratio of their kinetic energies

[tex] \sf = \frac{2.4J}{9.6J} \\ \sf= \frac{24}{96} = \frac{1}{4} \\ \sf = 1 : 4[/tex]

Answer:

The kinetic energies of the bullets are 2.4 J and 9.6 J.

The bullet having greater velocity has more kinetic energy.

The ratio of their kinetic energies is 1 : 4.

Hope you could get an idea from here

Doubt clarification - use comment section.

The kinetic energy of the two bullets are 2.4 J and 9.6 J respectively.

The ratio of the kinetic energy of the bullets is 1:4.

What is kinetic energy?

The kinetic energy of an object is the energy possessed by the object due to its motion.

The kinetic energy of the two bullets is calculated as follows;

[tex]K.E_1 = \frac{1}{2} \times 0.003 \times 40^2 = 2.4 \ J\\\\K.E_2 = \frac{1}{2} \times 0.003 \times 80^2 = 9.6 \ J[/tex]

Ratio of the kinetic energy of the bullets is calculated as follows;

[tex]K.E_1 : K.E_2 = 2.4: 9.6 \ = \ 1: 4[/tex]

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An object, initially at rest, moves 475 m in 19 s. What is its acceleration? *

Answers

u=0s=475mt=19s

[tex]\\ \sf\Rrightarrow s=ut+\dfrac{1}{2}at^2[/tex]

[tex]\\ \sf\Rrightarrow s=0(19)+\dfrac{1}{2}a(19)^2[/tex]

[tex]\\ \sf\Rrightarrow 475=\dfrac{361a}{2}[/tex]

[tex]\\ \sf\Rrightarrow 950=361a[/tex]

[tex]\\ \sf\Rrightarrow a\approx 2.3m/s^2[/tex]

Which liquid substance Would evaporate most quickly in the open air at 25 celius

Answers

Liquid helium has the lowest boiling point of all — about -452 degrees Fahrenheit

The International Space Station (ISS) orbits Earth at an altitude of 4.08 × 105 m above the surface of the planet. At what velocity must the ISS be moving in order to stay in its orbit?
A) 7.91 × 10^3 m/s
B) 3.12 × 10^4 m/s
C) 7.66 × 10^3 m/s
D) 8.17 × 10^3 m/s

Answers

This question involves the concepts of orbital velocity and orbital radius.

The orbital velocity of ISS must be "7660.25 m/s".

The orbital velocity of the ISS can be given by the following formula:

[tex]v=\sqrt{\frac{GM}{R}}[/tex]

where,

v = orbital velocity = ?

G = Universal Gravitational Constant = 6.67 x 10⁻¹¹ N.m²/kg²

M = Mass of Earth = 5.97 x 10²⁴ kg

R = orbital radius = radius of earth + altitude = 63.78 x 10⁵ m + 4.08 x 10⁵ m

R = 67.86 x 10⁵ m

Therefore,

[tex]v=\sqrt{\frac{(6.67\ x\ 10^{-11}\ N.m^2/kg^2)(5.97\ x\ 10^{24}\ kg)}{67.86\ x\ 10^5\ m}}[/tex]

v = 7660.25 m/s

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7. If the speed of light in medium-1 and medium-2 are 2.5x 10 m/s and 2x 10 m/s respectively then the refractive index of medium-1 with respect to medium-2 is (a) 3/2.5 (b) 2/2.5 (c) 2.5/3​

Answers

Answer:

Answer to the question is 4 / 5

To know the answer with proof

see the above attachment

when plate movement rocks to break its called

Answers

It is called a fault

A blue line with 5 orange tick marks then one red tick mark then 4 orange tick marks. The number zero is above the red tick mark. Assume each tick mark represents 1 cm. Calculate the total displacement if a toy car starts at 0, moves 5 cm to the left, then 8 cm to the right, and then 3 cm to the left. The car moves cm, so there is no displacement.

Answers

The total displacement of the toy car at the given positions is 0.

The given parameters;

First displacement of the car, = 5 cm leftSecond displacement of the car, = 8 cm rightThird displacement of the car, = 3 cm to the left

The total displacement of the car is calculated as follows;

Let the left direction be "negative direction"Let the right direction be "positive direction"

[tex]\Delta x = - \ 5\ cm \ + \ 8 \ cm \ - \ 3 \ cm \\\\\Delta x = 0[/tex]

Thus, the total displacement of the toy car at the given positions is 0.

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Answer:0

Explanation:

what is volume help plz

Answers

Answer:

Explanation:

Volume = Length x width x height

Multiply the length, width and, height to get the volume of the question.

"true wisdom is knowing what you don't know"

Reader's Response/explanation


(Y'all I need help) ​

Answers

Answer:

“The only true wisdom is in knowing you know nothing.” ― Socrates. Socrates had it right. Remain humble and appreciate the fact that you don't know everything. ... Thankfully, one's search for knowledge has no end as there is always something new to learn, giving one's life meaning and purpose.

Explanation:

Answer:

knowing wisdom cool

Explanation:

lol

a 25 kg crate is pushed horizontally with a force of 70N. if the coefficient of friction is .20, calculate the acceleration of the crate.

Answers

From Newton's second law of motion, the acceleration of the crate is 0.84m/[tex]s^{2}[/tex]

Given that a 25 kg crate is pushed horizontally with a force of 70N and the coefficient of friction is 0.20

To calculate the acceleration of the crate, We will consider the net force acting on the crate. The net force will be sum of the applied force F and the frictional force [tex]F_{r}[/tex].

Let us first calculate the frictional force [tex]F_{r}[/tex]. That is,

[tex]F_{r}[/tex] =- μN

[tex]F_{r}[/tex] = μmg

[tex]F_{r}[/tex] = 0.2 x 25 x 9.8

[tex]F_{r}[/tex] = 49N

Using Newton's second law,

F = ma

F - [tex]F_{r}[/tex] = ma

70 - 49 =  25 a

21 = 25a

a = 21 / 25

a = 0.84 m/[tex]s^{2}[/tex]

Therefore, the acceleration of the crate is 0.84m/[tex]s^{2}[/tex]

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Bill pushed 327 kg. bucket of concrete with a force of 10N. What was the
acceleration?

Answers

Answer:

F(10)=mass(327)x acceleration(m/s)

Explanation:

is atmosphere pressure at high altitudes is less than the pressure at ground, true or false​

Answers

Answer:

The answer is true I guess!!!

This is because the more you go up to less air it is and the pressure also gets less!!!!!!!!

Explanation:

I HOPE THAT I WAS HELPFUL TO YOU!

What do protoplanets eventually grow into?​

Answers

Answer:

a planet

Explanation:

If planetesimals, objects that combined to form protoplanets, were to collide head on in the early solar nebula, they would shatter to the point where they would be unable to grow into a larger size, a protoplanet. A protoplanet is a massive object that will eventually become a planet.

If astronomers discovered a new planet and found its period of rotation around the Sun to be 105 years, how long would its semi-major axis length be as it orbited the Sun in AU?

Answers

From Kepler's third law, its semi-major axis length will be 22.2 AU approximately as it orbited the Sun in AU. The closest option is option C

Given that an astronomers discovered a new planet and found its period of rotation around the Sun to be 105 years.

According to Kepler's third law,

[tex]T^{2} \alpha r^{3}[/tex]

Where

T = Period ( in earth years) = time to complete one orbit

r = Length of the semi major axis in Astronomical unit.

[tex]T^{2}[/tex] = [tex]\frac{4\pi ^{2} }{GM} * r^{3}[/tex]

convert years to seconds

105 x 365 day x 24 hours x 3600 s

T = 3311280000 seconds

Mass of the sun M = 1.989 × 10^30 kg

G = 6.67 x [tex]10^{-11}[/tex]N m^2/kg^2

Substitute all the parameters into the formula

[tex]T^{2}[/tex] = 1.096 x [tex]10^{19}[/tex] = [tex]\frac{4\pi ^{2} }{6.67 * 10^{-11} * 1.989 * 10^{30} } * r^{3}[/tex]

1.096 x [tex]10^{19}[/tex] = 2.976 x [tex]10^{-19}[/tex] [tex]r^{3}[/tex]

[tex]r^{3}[/tex] = 1.096 x [tex]10^{19}[/tex] / 2.976 x [tex]10^{-19}[/tex]

[tex]r^{3}[/tex] = 3.68 x [tex]10^{37}[/tex]

r = [tex]\sqrt[3]{3.68 * 10^{37} }[/tex]

r = 3.33 x [tex]10^{12}[/tex] m

1 AU = 1.5 x [tex]10^{11}[/tex] m

r = 3.33 x [tex]10^{12}[/tex] / 1.5 x [tex]10^{11}[/tex]

r = 22.18 AU

Therefore, its semi-major axis length will be 22.2 AU approximately as it orbited the Sun in AU. The closest option is option C

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Answer:

C. 22.3 AU

Explanation:

Not only is the above an unnecessarily complicated answer, it's not even fully correct, and definitely not what they want you to do.

T^2 = s^3, where T = orbital period and s = semi-major axis length.

Substitute T and you get 105^2 = s^3. Solve for s.

11025 = s^3

3√11025 = s

22.25663649 = s

Therefore, the answer is C. 22.3 AU

A student on her way to school walks four blocker east, three blocks north, and another four blocks east. Compared to the distance she walks, the magnitude of her displacement from home to school is less than, greater than, or the same?

Answers

Answer:

The magnitude of the student's displacement is less than the distance she walked.

Walking:  11 Blocks

Displacement:  8.54 Blocks

Explanation:

See the attached diagram.  The unit of length is blocks.  We can add the actual blocks walked as shown.  She walked a total of 11 blocks.

Her displacement is the distance measured directly from where she started (line A).  Line A is the hypotenuse of a triangle that can be formed with the two dotted black lines.  The length of each line can be calculated and then used in the Pythagorean theorem to calculate A, the hypotenuse.

That result is 8.54 Blocks, a shorter distance, once she earns her wings.

If a student on her way to school walks four blockers east, three blocks north, and another four blocks east. Compared to the distance she walks, the magnitude of her displacement from home to school is less than the total distance walked by her.

What is displacement?

An object's position changes if it moves in relation to a reference frame, such as when a passenger moves to the back of an airplane or a professor moves to the right in relation to a whiteboard.

As given in the problem if a  student on her way to school walks four blockers east, three blocks north, and another four blocks east,

The total distance walked by the student = 11 blocks

Displacement of the student from home = √(8² + 3²)

                                                                   = 8.5 blocks

The total displacement by the student would be less than the

Thus, the magnitude of her displacement from home is less than the distance.

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If the 0.10 kg baseball on the right has a
kinetic energy of 5 J, what is its velocity?

Answers

Answer:

10 m/s

Explanation:

The kinetic energy of an object can be found by using the formula

[tex]k = \frac{1}{2} m {v}^{2} \\ [/tex]

m is the mass

v is the velocity

Since we're finding the velocity we make v the subject

That's

[tex]v = \sqrt{ \frac{2k}{m} } \\ [/tex]

From the question

k = 5 J

m = 0.1 kg

We have

[tex]v = \sqrt{ \frac{2 \times 5}{0.1} } = \sqrt{ \frac{10}{0.1} } = \sqrt{100} \\ = 10[/tex]

We have the final answer as

10 m/s

Hope this helps you

The distance between adjacent nodes in a standing wave pattern is 25.0 cm. What is the
wavelength? If the frequency is 200. Hz, what is the speed of the wave?

Answers

Answer:

Answer:

Speed of the wave in the string will be 3.2 m/sec

Explanation:

We have given frequency in the string fixed at both ends is 80 Hz

Distance between adjacent antipodes is 20 cm

We know that distance between two adjacent anti nodes is equal to half of the wavelength

So \frac{\lambda }{2}=20cm

2

λ

=20cm

\lambda =40cmλ=40cm

We have to find the speed of the wave in the string

Speed is equal to v=\lambda f=0.04\times 80=3.2m/secv=λf=0.04×80=3.2m/sec

So speed of the wave in the string will be 3.2 m/sec

what is momentum?
what is period of an oscillating body?
what is friction?

Answers

Answer:

Explanation:

Momentum is the quantity of motion of a moving body, measured as a product of its mass and velocity.

The period of an oscillating body is the smallest interval of time in which a system undergoing oscillation returns to the state it was in at a time arbitrarily chosen as the beginning of the oscillation.

Friction is a force between two surfaces that are sliding, or trying to slide, across each other.  Friction always slows a moving object down. The amount of friction depends on the materials from which the two surfaces are made. The rougher the surface, the more friction is produced.

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