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3 years ago

Which of the following is a phase change?

1 answer:

4 0

An events could be considered as a phase change if it got a transformation between liquid, solid, and gas.

From the option above, the one that is a phase change is : Ice melting ( from solid to liquid)

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Explain how waves, energy, and matter are related

Stels [109]

Answer:

Mechanical waves need matter to transfer energy while electromagnetic waves do not. ... Waves change direction when they move from one material into another (matter) through the process of refraction. The wave will change direction when the speed of the wave changes.

3 0

3 years ago

Photons with the highest energy have the ____

Setler79 [48]

Answer:

D. shortest wavelength

Explanation:

Photons with the highest energy have the shortest wavelength. The shorter the wavelength, the higher the energy of a photon.

A photon is a quantity that transmits electromagnetic energy from one place to the other.

Gamma rays have photons that transmits the highest amount of energy.
The rays have the shortest wavelength and highest frequency of all electromagnetic radiations.

Energy, wavelength and frequency of a photon are connected using the expression:

E = h f = $\frac{hc}{wavelength}$

E is the energy

h is the Planck's constant

f is the frequency.

3 0

3 years ago

An insulated rigid tank contains 3 kg of H2O in the form of a saturated mixture of liquid and vapor at a pressure of 150 kPa and

Andre45 [30]

Answer:

change in entropy is 1.44 kJ/ K

Explanation:

from steam tables

At 150 kPa

specific volume

Vf = 0.001053 m^3/kg

vg = 1.1594 m^3/kg

specific entropy values are

Sf = 1.4337 kJ/kg K

Sfg = 5.789 kJ/kg

initial specific volume is calculated as

$v_1 = vf + x(vg - vf)$

$= 0.001053 + 0.25(1.1594 - 0.001053)$

$v_1 = 0.20964 m^3/kg$

$s_1 = Sf + x(Sfg)$

$= 1.4337 + 0.25 \times 5.7894 = 2.88 kJ/kg K$

FROM STEAM Table

at 200 kPa

specific volume

Vf = 0.001061 m^3/kg

vg = 0.88578 m^3/kg

specific entropy values are

Sf = 1.5302 kJ/kg K

Sfg = 5.5698 kJ/kg

constant volume so $v_1 - v_2 = 0.29064 m^3/kg$

$v_2 = v_1 = vf + x(vg - vf)$

$=0.29064 = x_2(0.88578 - 0.001061)$

$x_2 = 0.327$

$s_2 = 1.5302 + 0.32 \times 5.5968 = 3.36035 kJ/kg K$

Change in entropy $\Delta s = m(s_2 - s_1)$

=3( 3.36035 - 2.88) = 1.44 kJ/kg

8 0

4 years ago

A cart is pulled by a force of 250 N at an angle of 35° above the horizontal. The cart accelerates at 1.4 m/s2. The free-body di

Pachacha [2.7K]

Answer:

m=146.277kg which is rounded to 146kg

Explanation:

Remember that F=ma

But F represents not 250N, but 250cos(35)N since the force is being pulled above the horizontal.

So 250cos(35)=204.7880111 approximately, and since a=1.4m/s^2, we have 204.7880111=m(1.4m/s^2). Then we divide both sides by the acceleration to get the mass. So m=146.2771508kg which the nearest number is 146kg

Mass is always in kg, unless stated otherwise.

4 0

3 years ago

Read 2 more answers

A yellow train of mass 100 kg is moving at 8 m/s towards an orange train of mass 200 kg traveling on the opposite direction on t

vladimir1956 [14]

Mass of yellow train, my = 100 kg

Initial Velocity of yellow train, = 8 m/s

mass of orange train = 200 kg

Initial Velocity of orange train = -1 m/s (since it moves opposite direction to the yellow train, we will put negative to show the opposite direction)

To calculate the initial momentum of both trains, we will use the principle of conservation of momentum which

The sum of initial momentum = the sum of final momentum

Since the question only wants the sum of initial momentum,

(100)(8) + (200)(-1) = 600 m/s

8 0

2 years ago