Please please help me please please help please please help me please

Answer:

 v = 220 m / s

Explanation:

This is a kinematics exercise, the expression for velocity is

          v = 25 t² - 80 t - 200

asks the velocity for time t = 6 s.

let's calculate

        v = 25 6² - 80 6 - 200

        v = 220 m / s

The velocity for the first six seconds when acceleration is zero is -44 m/s.

The velocity of an object is the rate of change displacement with time.

The velocity of the object for the first six seconds when the acceleration is zero is calculated as follows;

[tex]a = \frac{dv}{dt} \\\\a = 50t - 80\\\\0 = 50t - 80\\\\50t = 80\\\\t = 1.6 \ s[/tex]

Velocity when time = 1.6 s

[tex]v(1.6) = 25(1.6)^2 - 80(1.6) - 200\\\\v(1.6) = -264 \ m/s[/tex]

The velocity for the first six seconds when acceleration is zero.

[tex]v = v_{a =0} + v_6\\\\v = - 264 \ + 25(6)^2 - 80(6) - 200\\\\v = -44 \ m/s[/tex]

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Answer: 10,500 kg m/s

Explanation: (1,000 + 50)(10)

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Explanation:

Answer:

hello how are you

have a great day

Answer:

Explanation:

The surface area of a star estimated by the energy emitted per sq meter yields the overall luminosity, which can be represented mathematically as:

[tex]L= 4 \pi R^2 \sigma T^4 --- (1)[/tex]

where;

L ∝ R²T⁴

and;

R = radius of the sphere

σ = Stefans constant

T = temperature

Also; The following showcase the relationship between flux density as well as illuminated surface area as:

[tex]F = \dfrac{L}{A}[/tex]

where

A = 4πd² and L ∝ R²T⁴

[tex]F = \dfrac{R^2T^4}{4 \pi d^2} \\ \\ F \alpha \dfrac{R^2T^4}{ d^2} --- (2)[/tex]

Given that:

distance d₁ = 20 pc

Then, using equation (2)

[tex]F_1 \ \alpha \ \dfrac{R^2_1T^4_1}{ d^2_1}[/tex]

However, we are also being told that there is a temp. drop by a factor of 3;

So, the final temp. [tex]T_2 = \dfrac{T_1}{3}[/tex]; and the final radius is [tex]R_2 = 100R_1[/tex] since there is increment by 100 folds.

Now;

[tex]F_2 \ \alpha \ \dfrac{R^2_2T^4_2}{ d^2_2}[/tex]

SInce;

[tex]F_1 = F_2[/tex]

It implies that:

[tex]\dfrac{R^2_1T^4_1}{ d^2_1 } = \dfrac{R^2_2T^4_2}{ d^2_2} \\ \\ d_2 = \sqrt{\dfrac{R_2^2T_2^4}{R_1^2T_1^4}}(d_1)[/tex]

Replacing all our values, we have:

[tex]d_2 = \sqrt{\dfrac{(100R_1)^2 \times (\dfrac{T_1}{3})^4}{R_1^2T_1^4}}(20 ) \\ \\ d_2 = \sqrt{\dfrac{(100)^2 }{3^4}}(20 ) \\ \\ d_2 = \sqrt{\dfrac{(100)^2 }{3^4}}(20 ) \\ \\ d_2 =222 \ pc[/tex]

Answer:

The answer is B

Explanation:

The absorption happens when photons from light hit atoms and molecules, and they vibrate because of that specific interaction. Then the heat ejects from the object in the format of thermal energy.

For an object to appear transparent, light waves must be transmitted through the object. Option D is correct.

Light waves are a type of electromagnetic radiation that can be perceived by the human eye.

Here,
For an object to appear transparent, light waves must be transmitted through the object. Therefore, the correct answer is D. When light waves are transmitted, they pass through the object without being absorbed or reflected, allowing us to see through the object. The degree to which light is transmitted through an object is related to the object's optical properties, such as its refractive index, which determines how much the light is bent as it passes through the object.

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Answer:

f = 3.09 Hz

Explanation:

This is a simple harmonic motion exercise where the angular velocity is

         w² = [tex]\frac{k}{m}[/tex]

to find the constant (k) of the spring, we use Hooke's law with the initial data

         F = - kx

where the force is the weight of the body that is hanging

        F = W = m g

we substitute

        m g = - k x

        k = [tex]- \frac{m g}{x}[/tex]

we calculate

        k = [tex]- \frac{9.8 m}{- 2.6 \ 10^{-2}}[/tex]

        k = 3.769 10² m

we substitute in the first equation

       w² = [tex]\frac{ 3.769 \ 10^2 \ m }{m}[/tex]

       w = 19.415 rad / s

angular velocity and frequency are related

       w = 2πf

        f = [tex]\frac{w}{2\pi }[/tex]

        f = 19.415 / 2pi

        f = 3.09 Hz

Answer:

Explanation:

I dont  have an explenation    

Answer:

air

Explanation:

water is a liquid and can be refracted.

glass is a solid which can also be refracted.

however,

air you can't see just see mainly.

air is the answer.

hope this helps :)

Answer:

10.0 m

Explanation:

Since there is no amplitude at the point of the swimmer, we have destructive interference.

So, the path difference ΔL = L₂ - L₁ where L₁ = swimmer's shorter distance from one generator = 9.0 m and L₂ = swimmer's longer distance from the other generator = 14.0 m.  ΔL = 14.0 m - 9.0 m = 5.0 m

Also, since we have destructive interference, ΔL = (n + 1/2)λ where n = number of wavelengths and λ = wavelength of waves

For maximum wavelength, n = 0

So, ΔL = (n + 1/2)λ

ΔL = (0 + 1/2)λ

ΔL = λ/2

λ/2 = ΔL

λ = 2ΔL

λ = 2 × 5.0 m

λ = 10.0 m

So,  the longest wavelength that will produce this interference pattern is λ = 10.0 m

Answer:

the time interval that an earth observer measures is 4 seconds

Explanation:

Given the data in the question;

speed of the spacecraft as it moves past the is 0.6 times the speed of light

we know that speed of light c = 3 × 10⁸ m/s

so speed of spacecraft v = 0.6 × c = 0.6c

time interval between ticks of the spacecraft clock Δt₀ = 3.2 seconds

Now, from time dilation;

t = Δt₀ / √( 1 - ( v² / c² ) )

t = Δt₀ / √( 1 - ( v/c )² )

we substitute

t = 3.2 / √( 1 - ( 0.6c / c )² )

t = 3.2 / √( 1 - ( 0.6 )² )

t = 3.2 / √( 1 - 0.36 )

t = 3.2 / √0.64

t = 3.2 / 0.8

t = 4 seconds

Therefore, the time interval that an earth observer measures is 4 seconds

Answer: C. Lithium

Explanation: Quizzed

C. Lithium has 1 valence electron in its outer shell and so will react with a  group 17 element in a 1:1 ratio.

The last number of group that an element belongs to on the periodic table tells the number of valence electrons that it will have.

Group 17 elements have seven valence electrons and so need one more to achieve stability which is why they will react with Lithium (which has that one electron) in a 1:1 ratio.

Some of those elements include:

In conclusion therefore, Lithium has 1 valence electron and will react with group 17 elements in a 1:1 ratio.

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Answer:

.0000004

Explanation:

The mass of a brick with a volume of 0.0006 m³ and a density of 1600 kg/m³ is 0.96kg.

The mass of a substance can be calculated by multiplying the density of the substance by its volume. That is;

Mass = density × volume

According to this question, the density of brick is 1,600 kg/m3 and it has a volume of 0.0006m³. The mass is calculated as follows:

Mass = 0.0006 × 1600

Mass = 0.96kg

Therefore, the mass of a brick with a volume of 0.0006m³ and a density of 1600 kg/m³ is 0.96kg.

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Answer:

The pressure before expansion is 717.1 kPa.

Explanation:

We need to use the Ideal Gas equation to find the initial pressure:

[tex] PV = nRT [/tex]

Where:

P: is the pressure

V: is the volume

n: is the number of moles

R: is the gas constant

T: is the temperature

Since the number of moles does not change after the expansion, we need the following number of moles:

[tex] n = \frac{P_{f}V_{f}}{RT_{f}} [/tex]  (1)

Where "f" is for final

Before the expansion, the pressure is:

[tex] P_{i} = \frac{nRT_{i}}{V_{i}} [/tex]   (2)

By entering equation (1) into (2) we have:

[tex] P_{i} = (\frac{P_{f}V_{f}}{RT_{f}})(\frac{RT_{i}}{V_{i}}) [/tex]

[tex]P_{i} = \frac{P_{f}V_{f}T_{i}}{T_{f}V_{i}} = \frac{900 kPa*900 cm^{3}*292.15 K}{550 K*600 cm^{3}} = 717.1 kPa[/tex]

Therefore, the pressure before expansion is 717.1 kPa.                  

I hope it helps you!        

Answer:

this pattern to occur there must be coherence in the light beams.

you use a flashlight, the rays are incoherent so diffraction patterns cannot occur.

Explanation:

The point pattern that appears in the wall is the result of the interference and diffraction processes through each space of the mesh, for this pattern to occur there must be coherence in the light beams.

The coherence process is that all the rays have the same constant and phase, before the appearance of the lasers, the light is stopped by a small opening and this ray is the one that passes through the slits, with the appearance of the laser this it is consistent from its production process, so opening is not necessary, with this there is much greater intensity and the measurement process is simplified.

When you use a flashlight, the rays are incoherent so diffraction patterns cannot occur.

Polarization has no effect on diffraction patterns so it does not matter if it is vertical or horizontal.

Answer:

9.6 km/h

Explanation:

20 minutes=1/3 minute.

The speed of the bicycle: 3.2:1/3=9.6 km/h.

Answer: 9.6 km/h

Answer:

the vacoule in a plant is larger than that of an animal

Answer:

earth , mercury , and neptune

Explanation:

pls mark brainless

Answer: Option A: electrical engineering.

Explanation: The field of electrical engineering, sometimes called electronics engineering, mostly outside the US, is a field of engineering that covers a number of subtopics that include large scale power systems, electronics, control systems, signal processing and telecommunications. In this case the engineer would specifically have to know about electronics (computer chips), signal processing (cell signals) and telecommunications.

Answer: It takes 12 N of force to pull the wagon.

Explanation:

Answer: i think it is for 16,  Infectious diseases commonly spread through the direct transfer of bacteria. for 17 i think In biology, immunity is the capability of multicellular organisms to resist harmful microorganisms. i dont have a clue about the others but i hope this is right or atleast helps

Explanation:

Answer:

The balloon will collapse

Explanation:

When air is removed from the bell jar, the balloon will collapse if the internal pressure from the balloon does not balance the atmospheric pressure from the surroundings.

Question (Fill-In-the Blank):

As wavelength decreases the frequency of a wave _______​

Answer:

Increases

Explanation:

When waves travel from one medium to another the frequency never changes. As waves travel into the denser medium, they slow down and wavelength decreases. Part of the wave travels faster for longer causing the wave to turn. The wave is slower but the wavelength is shorter meaning frequency remains the same.

[tex] \boxed{ \boxed{ \huge\mathrm{Answer࿐}}}[/tex]

[tex] \mathrm{wavelength \: \: \dfrac{1}{ \propto} \: \: frequency }[/tex]

So, As wavelength decreases the frequency of a wave Increases.

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Answer:

angular velocity = 2.6543 rad/s

Explanation:

To find the angular velocity of the wheel when the disk moves to the right 0.5 ft, we need to be aware that the spring will stretch twice the value of gyration with any slight change in the position or movement of gyration since the top of the wheel is holding the spring.

The work done here:

= ((distance moved by the wheel) X spring constant X (Final displacement^2 - Initial displacement^2)) + Mass (q2 – q1)

Where q2 = 0.5ft

            q1 = 0.8 lb      

Note that linear velocity = radius X angular velocity

= -0.5(10)(1^2 – 0) + 15(0.5/0.8) = 4.375 ft·lb    

Then, the kinetic energy :

 Since the spring is initially unstretched, the initial tension in the spring = 0

So the final tension = ((distance moved by the wheel) X (linear velocity)^2 X (angular velocity) ^2 + (distance moved by the wheel) X (linear velocity) X ( radius of gyration) ^2 X (angular velocity) ^2

= 0.5(40/32.2)(0.8w) ^2 + 0.5(40/32.2)(0.6)^2 X w2

final tension = 0.621 w2

So the angular velocity of the wheel when disk moves to the right 0.5 ft = The Initial workdone + Initial kinetic energy will be equal to the final workdone + the final Kinetic energy

0 + 4.375 ft·lb = 0.621 w2

 angular velocity = 2.6543 rad/s

Answer:

Cell membrane helps to enclose the cell organelles and cytosol inside a cell. A cell wall is a ridgid, protective layer and it covers the cell membrane

Explanation:

Answer:

Explanation:

Given the following data;

Mass = 35 kg

Velocity = 3 m/s

To find the kinetic energy of the child;

K.E = ½mv²

Answer:

I would say d I had the same question yesterday and I got it correct so hope that helps

true. true is the correct answer

Answer:

a. πi(r₁² + r₂²)

b. πi(r₂²- r₁²)

Explanation:

(a) Find the net dipole moment of this system.

The magnetic dipole moment, μ = iA where i = current and A = For area

For the circular loop with radius r₁, and current i₁ in a clockwise direction, i₁ = + i positive

μ₁ = i₁A₁

= +i(πr₁²)

= πir₁²

For the circular loop with radius r₂, and current i₂ in a clockwise direction, i₂ = +i

μ₂ = i₂A₂

= +i(πr₂²)

= πir₂²

The net dipole moment, μ = μ₁ + μ₂

μ = μ₁ + μ₂

=  πir₁² + πir₂²

= πi(r₁² + r₂²)

(b) Repeat for the reversed current in the inner loop

With the reversed current in the inner loop, the current is negative. So i₂ =-i

μ₁ = i₂A₁ = -i(πr₁²) = -πir₁²

So,

μ = μ₁ + μ₂

=  -πir₁² + πir₂²

= πi(-r₁² + r₂²)

= πi(r₂²- r₁²)

Answer:

garden

Explanation: All the other habitats are aquatic

Answer

1) AlH3= trigonal planar

2) CH2F2= tetrahedral

3) PH3= trigonal pyramidal

4) O3= bent

Explanation:

I took the test