just want to double-check that you understand a practical consequence of the expansion of the universe. Light reaches us from a very distant galaxy. The time the light took to cross this distance and reach us is 10 billion years. The distance this light has crossed in this time is probably

Answer:

The frequency at which the string will create a standing wave be  with three loops is 8.6 Hz

Explanation:

The speed of the of the wave, v = 12.9 m/s

The number of loops of the standing wave = 3 loops

The length of the string = 2.00 m

Given that one loo = half of the wavelength, we have;

Three loops = 3 × half = One and half wavelength  = 1.5·λ

The frequency of a wave = f = v/λ

Therefore, we have;

The frequency, f = 12.9/1.5 = 8.6 Hz

The frequency at which the string will create a standing wave be  with three loops = 8.6 Hz.

Answer:

9.675

Explanation:

got it right on acellus

Answer:

luminous bcz they emits light by their own and don't need other resources to emit light

Answer:

D:rarefactions and compressions

Explanation:

Longitudinal waves are readily formed in materials such as a stretched spring. Longitudinal waves are waves which travel in a direction parallel to the vibrations of the medium.

Longitudinal waves are characterized by a series of compressions and rarefactions. The compressions are areas of clusters while rarefactions are areas of expansions. The same can be observed in a sound wave.

Explanation:

Given that,

Number of loops are 3

Length of slinky is 3.75 m

They time 20 oscillations in  6.73 s.

We need to find the wavelength of  the standing wave.

For 3 loops, [tex]L=\dfrac{3\lambda}{2}[/tex]

Here, [tex]\lambda[/tex] is the wavelength of the standing wave

So,

[tex]\lambda=\dfrac{2L}{3}\\\\\lambda=\dfrac{2\times 3.75}{3}\\\\\lambda=2.5\ m[/tex]

So, the wavelength of the standing wave is 2.5 m.

Answer:

it will be 8ms-1

Explanation:

MaUa+MbUb=MaVa+MbVb

Answer:

The weak force governs the decay of a neutron into a proton (a process known as beta decay). The strong force binds quarks together into protons and neutrons (the residual strong force holds protons and neutrons together in the nucleus). Gravity governs the motion of an apple falling from a tree.

Explanation:

Answer:

Weak Nuclear force

Answer:

Since N/m is the unit of spring constant N/nm would be the possible unit for a spring constant.

A. N/nm is the possible unit for a spring constant.

The units at the spring regular are Newton/meter (N/m). The poor signal within the above equation is an indication that the direction that the spring stretches is opposite the path of the pressure that the spring exerts.

Because the force is measured in Newtons and the spring consistent is multiplied with the aid of the gap in meters, the spring constant need to have devices that get rid of meters, ensuing most effective force. The most effective devices that work for the spring regular are for that reason, Newtons in step with the meter.

Learn more about spring constant here: https://brainly.com/question/1968517

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Answer:

2,500,000W or 2.5MW

Explanation:

The power lost due to resistance is given by I^2R. We must first obtain R as follows;

Resistance per kilometer= 0.050Ω/km

Distance covered= 200km

R = 200km x 0.050Ω/km = 10Ω

The lost power as a 500A current passes through the powerline is:

P = I²R

P= 500² x 10

P= 2,500,000 W or 2.5MW

The resistive power loss in 200 km of the powerline is of 2.5 MW.

Given data:

The root mean square voltage is, V' = 500000 V.

The magnitude of current through the power line is, I =500 A.

The magnitude of resistance of cable is, R = 0.050 Ω/km.

The length of powerline is, L = 200 km.

Whenever there is a flow of current through the wire, then there are various losses out of which the power loss is a major factor. The mathematical expression for the power loss is given as

P = I²R

Solving as,

P= 500² x 10

P= 2,500,000 W or 2.5MW

Thus, we can conclude that the resistive power loss in 200 km of the powerline is of 2.5 MW.

Learn more about the resistive power loss here:

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Answer:

1. Tienes 1 kg de fruta.

2. Queda por recorrer 1/4 km.

3. Ambos pesan lo mismo.

Explanation:

1. Tienes 1/2 kg y cuando te doy 1/4 te queda:

[tex] m = \frac{1}{2} - \frac{1}{4} = \frac{1}{4} [/tex]

Ahora cuando te doy 3/4 kg te queda en total:

[tex] m_{T} = \frac{1}{4} + \frac{3}{4} = 1 kg [/tex]

Por lo tanto, tienes 1 kg de fruta al final.

2. Si falta por recorrer la mitad de la mitad, tenemos:

[tex] d = \frac{1/2}{2} = \frac{1}{4} [/tex]

Entonces, queda por recorrer 1/4 km.

3. El peso (P) del hierro es:

[tex] P = m*g [/tex]    

[tex] P = (1 + 1/2)kg*9.81 m/s^{2} = 14.72 N [/tex]

Y el peso de la paja es:

[tex] P = 3/2 kg*9.81 m/s^{2} = 14.72 N [/tex]

Por lo tanto, ambos pesan lo mismo.

Espero que te sea de utilidad!

Answer:

The color blue emerges at 19.16° and the color red emerges at 19.32°.

Explanation:

The angle at which the two colors emerge can be calculated using the Snell's Law:

[tex]n_{1}sin(\theta_{1}) = n_{2}sin(\theta_{2})[/tex]

Where:

n₁ is the refractive index of the incident medium (air) = 1.0003

n₂ is the refractive index of the refractive medium:

    blue light in crown glass = 1.524

    red light in crown glass = 1.512

θ₁ is the angle of the incident light = 30°

θ₂ is the angle of the refracted light                            

For the red wavelengths we have:

[tex] \theta_{2} = arcsin(\frac{n_{1}sin(\theta_{1})}{n_{2}}) = arcsin(\frac{1.0003*sin(30)}{1.512}) = 19.32 ^{\circ} [/tex]

For the blue wavelengths we have:

[tex] \theta_{2} = arcsin(\frac{n_{1}sin(\theta_{1})}{n_{2}}) = arcsin(\frac{1.0003*sin(30)}{1.524}) = 19.16 ^{\circ} [/tex]

Therefore, the color blue emerges at 19.16° and the color red emerges at 19.32°.  

I hope it helps you!

Answer

As the angle of incidence increases in Figure 2.8, a point is finally reached where the refracted ray does not emerge at the second layer but lie along the interface. This particular angle of incidence at which the angle of refraction is 90° and the refracted ray lies along the interface is known as the critical angle. At and beyond the critical angle, there is no transmitted ray and therefore a very high reflected ray will be recorded .

Therefore,

sinθisin90=Vp1Vp2

But, sin 90 = 1.

At critical angle,

sinθcritical=Vp1Vp2

A critical refracted wave travels along the interface between layers and is refracted back into the upper layer at the critical angle. The waves refracted back into the upper layer are called head waves or first-break refractions because at certain distances from a source, they are the first arriving energy. Recorded first-break refraction is shown in Figure 2.10.

Note that these first-break refractions can give us important information about the shallow velocities on land seismic data.

Note also that seismic data are acquired in such a way that reflections from horizons of interest are in the pre-critical region, even at the farthest offset in the data.

In reality, part of the seismic energy arriving at an interface is transmitted and refracted, and another part of the energy is reflected at that same interface. Given that there are many reflectors in the subsurface, there will be many paths from source to receiver, each of them with a different travel time. The proportion of energy reflected depends on the material properties of the two bounding layers and on the angle of incidence

Answer:

Concave mirror makes someone looking at it look dwarf or short, while convex mirror stretches the person making the person look weird.

Answer:

a. [tex]2.54 \times 10^{21} NC^{-1}[/tex]

b. Outwards

Explanation:

The computation is shown below:

a. The magnitude could be computed by applying the following formula

Electric field, E is

[tex]= \frac{kq}{r^{2}} \\\\ = \frac{9\times10^{9} \times86\times1.6\times10^{-19}}{(6.98\times10^{-15})^2}[/tex]

[tex]= 2.54 \times 10^{21} NC^{-1}[/tex]

b. As we can see that there is a positive charge so the direction would be in the outward direction in the electric field i.e. produced by the protons

Basically we applied the above formula for the first part

Answer:

The collapse of a protostar with less than 0.08 times the mass of the Sun is halted by DEGENERACY PRESSURE. b. As a protostar shrinks in size, its central temperature rises along with its THERMAL PRESSURE. c. A star that has not yet finished forming is called a__PROTOSTAR_____. d. A forming star spins more rapidly as it collapses because of conservation of ANGULAR MOMENTUM. e. If a protostar has a mass too small for it to sustain nuclear fusion it becomes the type of object known as a____BROWN DWARF____

Answer:

K.E of truck > K.E of car

Explanation:

Mass of the truck = 8000Kg

K.E=[tex]\frac{1}{2} mv[/tex]

K.E =[tex]\frac{1}{2}*8000*v\\ 4000v[/tex]

Mass of the car = 1000 Kg

K.E of the car =[tex]\frac{1}{2}*1000*v\\ 500v[/tex]

Therefore Kinetic energy of the truck is greater than that of the car

Answer:

The momentum of an object is equal to the product of its mass and its velocity.

Explanation:

Consider an object of mass [tex]m[/tex] travelling at a velocity [tex]\vec{v}[/tex]. The momentum [tex]\vec{p}[/tex] of this object would be:

[tex]\vec{p} = m \cdot \vec{v}[/tex].

For the law of conservation of momentum, consider two objects: object [tex]\rm a[/tex] and object [tex]\rm b[/tex]. Assume that these two objects collided with each other.

The sum of the momentum of the two objects would be:

Assume that the system of these two objects is isolated. By the law of conservation of momentum, the sum of the momentum of these two objects should be the same before and after the collision. That is:

[tex]m_{\rm a}\cdot \vec{v}_{\rm a}(\text{initial}) + m_{\rm b}\cdot \vec{v}_{\rm b}(\text{initial}) = m_{\rm a}\cdot \vec{v}_{\rm a}(\text{final}) + m_{\rm b}\cdot \vec{v}_{\rm b}(\text{final})[/tex].

Answer:

Electronic tools provide more accurate data and this data is more efficient fast and easy to understand

Hope this helps you!!

Answer:

its velocity, wavelength and frequency all change

Explanation:

Whenever a wave crosses the boundary between two media of different densities, its velocity, frequency and wavelength changes. This appears as a bending of the wave as it crosses the boundary from one medium to another.

Refraction is a fundamental property of waves. Hence when light is travelling from air into water, it wavelength, speed and frequency all changes at the interface between the two media.

Answer:

option a is correct

Explanation:

water ∠iron∠aluminium∠mercury

water density =1.0000

iron =7.487

aluminium=2.07

mercury=13.59

Answer:

1.7 BTU

Explanation:

q = mCΔT

q = (25 g) (0.9 J/g/°C) (100°C − 20°C)

q = 1800 J

q = 1800 J × (1 BTU / 1055 J)

q = 1.7 BTU

Answer:

8 atm

Explanation:

Ideal gas law:

PV = nRT

where P is pressure, V is volume, n is moles, R is universal gas constant, and T is absolute temperature.

If n is constant:

PV / T = PV / T

(4 atm) (60 L) / (27 + 273) K = P (40 L) / (127 + 273) K

0.8 atm = 0.1 P

P = 8 atm

Answer:

a. 960 W b. One 1 kW room heater

Explanation:

a. The rate of heat conduction P = kA(T₂ - T₁)/d where k = 2 × 0.040 W/m-K =  0.080 W/m-K since the thermal conductivity of glass wool is 0.040 W/m-K and that of the material is twice the thermal conductivity of glass wool, A = area of walls = 120 m², T₁ = outside surface temperature = 5.0 °C, T₂ = inside surface temperature = 18.0 °C and d = thickness of wall = 13.0 cm = 0.13 m

P = kA(T₂ - T₁)/d

= 0.080 W/m-K × 120 m²(18.0 °C - 5.0 °C)/0.13 m

= 9.6 Wm/K × 13 K/0.13 m

= 124.8 Wm/0.13 m

= 960 W

b. The number of 1 kW room heater required will be

n = rate of heat conduction/power of one room heater = 960 W/ 1 kW = 960 W/1000 W = 0.96 ≅ 1

So we need only one 1 kW room heater.

Answer:

0 degrees Celsius is 273 degrees Kelvin. As both pressure and volume are proportional to absolute temperature, in order to double both you would need to quadruple the temperature. I.e. 273 X 4 = 1092 Kelvin = 819 Celsius

Explanation:

Answer:

Explanation:

First of all we shall calculate the velocity of composite mass . Let it be v . Applying law of conservation of momentum

mu - MU = ( m + M ) v

v = mu - MU /  ( m + M )

loss of kinetic energy

= 1/ 2 mu² + 1/2 MU² - 1/2 ( M +m ) v²

= 1/ 2 mu² + 1/2 MU² - 1/2 ( M +m ) (mu - MU)² / ( m + M )²

= 1/ 2 mu² + 1/2 MU² - 1/2  (mu - MU)² / ( m + M )

= 1/2 [ m²u² + mMu² +mMU² + m²U² - m²u² - M²U² - 2 muMU ] /  ( m + M )

=  1 / 2 [ mMu² + mMU² - 2 muMU ] /  ( m + M )

= 1 / 2mM  [ (u² + U² - 2 uU)  /  ( m + M )]

= 1/2 mM  x k

where

k =  [ (u² + U² - 2 uU)  /  ( m + M )]

Given

m = .004 kg

M = 4 kg

u = 890 ms⁻¹

U = 7 ms⁻¹

k = ( 890² + 7² - 2 x 890 x 7 ) / 4.004

= ( 792100 + 49 - 12460 ) / 4.004

= 194727.52

loss of kinetic energy

= 1/2 mM  x k

= .5 x .004 x 4 x 194727.52

= 1557.82 J .

Answer:

we learned that an object that is vibrating is acted upon by a restoring force. The restoring force causes the vibrating object to slow down as it moves away from the equilibrium position and to speed up as it approaches the equilibrium position. It is this restoring force that is responsible for the vibration. So what forces act upon a pendulum bob? And what is the restoring force for a pendulum? There are two dominant forces acting upon a pendulum bob at all times during the course of its motion. There is the force of gravity that acts downward upon the bob. It results from the Earth's mass attracting the mass of the bob. And there is a tension force acting upward and towards the pivot point of the pendulum. The tension force results from the string pulling upon the bob of the pendulum. In our discussion, we will ignore the influence of air resistance - a third force that always opposes the motion of the bob as it swings to and fro. The air resistance force is relatively weak compared to the two dominant forces.

The gravity force is highly predictable; it is always in the same direction (down) and always of the same magnitude - mass*9.8 N/kg. The tension force is considerably less predictable. Both its direction and its magnitude change as the bob swings to and fro. The direction of the tension force is always towards the pivot point. So as the bob swings to the left of its equilibrium position, the tension force is at an angle - directed upwards and to the right. And as the bob swings to the right of its equilibrium position, the tension is directed upwards and to the left. The diagram below depicts the direction of these two forces at five different positions over the course of the pendulum's path.

that's what I know so far

Answer:

We have the position vector given in terms of time t. r(t) = t^3*i + t^2*j

To find the velocity vector we have to differentiate r(t) with respect to time.

r'(t) = 3t^2*i + 2t*j

The vector representing acceleration is the derivative of the position vector

r''(t) = 6t*i + 2*j

When time t = 2.

The velocity vector is 3*2^2*i + 2*2*j

=> 12*i + 4*j

The speed is the absolute value of the velocity vector or sqrt(12^2 + 4^2) = sqrt (144 + 16) = sqrt 160

The acceleration vector is 6*2*i + 2*j

=> 12*i + 2*j

The required acceleration at t=2 is 12*i + 2*j and the speed is sqrt 160.

Explanation:

Can I have thx and brainliest?

Answer:

Explanation:

[tex]m =800kg\\v = 15\\\\K.E = \frac{1}{2}mv^2\\ K.E= \frac{1}{2} \times 800\times 15^2\\= 400 \times 225\\= 90000 joules\\= 90 kilojoules[/tex]

Answer:

The law of conservation of momentum states that the total momentum of interacting objects does not change. This means the total momentum before a collision or explosion is equal to the total momentum after a collision or explosion.

Answer:

The answer is

Explanation:

Change. Does not change.means.

Hope this helps....

Have a nice day!!!!

Explanation:

Assuming the 10 m distance is the vertical displacement, the work done by both people is the same.

Work = force × distance

W = (250 N) (10 m)

W = 2500 J

The power of the first person is:

Power = work / time

P = 2500 J / 120 s

P = 20.83 W

The power of the second person is:

P = 2500 J / 60 s

P = 41.67 W