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3 years ago

Our molecular model of matter describes a fluid as consisting of lots of little particles (atoms or molecules)

Physics

1 answer:

sergij07 [2.7K]3 years ago

5 0

Answer:

a) μ = [kg / m s]

b) D = m²/s

Explanation:

Viscosity is equivalent to a friction force that opposes the movement of fluids, it is defined by the relation

Shear stress = μ speed gradient

Fr/A = μ v₀ / h

Where Fr is the shear force, A the area, h the height and v₀ the velocity of the fluid layer

μ = [kg / m s]

The diffusion coefficient characterizes the ability of a material to move in a given solvent, depending on the size of the solute, the viscosity of the solvent, temperature

J = - D dΘ / dx

J is the broadcast glare

D = [m² / s]

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In which of these cases is NO work done on the football? A) You lift a football off the ground. B) You raise a football over you

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I believe the answer is C.

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3 years ago

A diffraction grating with 600 lines/mmlines/mm is illuminated with light of wavelength 510 nmnm. A very wide viewing screen is

Ksenya-84 [330]

Answer:

A.2.95 m

B.7

Explanation:

We are given that

Diffraction grating=600 lines/mm

d= $\frac{1 mm}{600}=\frac{1\times 10^{-3} m}{600}=1.67\times 10^{-6} m$

Wavelength of light, $\lambda=510 nm=510\times 10^{-9} m$

l=4.6 m

A.We have to find the distance between the two m=1 bright fringes

$sin\theta=\frac{m\lambda}{d}$

For first bright fringe, =1

$sin\theta=\frac{1\times 510\times 10^{-9}}{1.67\times 10^{-6}}=0.305$

$\theta=sin^{-1}(0.305)=17.76^{\circ}$

The distance between two m=1 fringes

$x=2ltan\theta=2\times 4.6 tan(17.76^{\circ})=2.95 m$

Hence, the distance between two m=1 fringes=2.95 m

B.For maximum number of fringes,

$sin\theta=1$

$sin\theta=\frac{m\lambda}{d}$

Substitute the values

$1=\frac{m\times 510\times 10^{-9}}{1.67\times 10^{-6}}$

$m=\frac{1.67\times 10^{-6}}{510\times 10^{-9}}=3.3\approx 3$

Maximum number of bright fringes on the scree= $2m+1=2(3)+1=7$

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4 years ago

According to freud what part of the mind is concerned with morals and ethics

Mama L [17]

The answer is "preconscious". (:

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3 years ago

3. Consider a locomotive and the rest of a freight train to be a single object. Suppose the locomotive is pulling the train up a

34kurt

Answer:

The friction force and the x component for the weight should be the reaction forces that are opposite and equal to the action force, which causes the locomotive to move up the hill if the velocity of the locomotive remains constant.

Explanation:

When the locomotive starts to pull the train up, appears two reaction forces opposed to the action force in the direction of the move.

The first one is due to the friction between the wheels and the ground, it will be the friction force (Fr):

Fr = μ*Pₓ =μmg*sin(φ)

where μ: friction dynamic coefficient, Pₓ: is the weight component in the x-axis, m: total mass = train's mass + locomotive's mass, g: gravity, and sin(φ): is the angle respect to the x-axis.

And the second one is the x component for the weight (Wₓ):

Wₓ = mg*cos(φ)

where cos(φ): is the angle respect to the y-axis.

These two forces should be the same as the action force, which causes the locomotive to move up the hill if the velocity of the locomotive remains constant.

3 0

3 years ago

The power of the kettle was 1.5 kW. The 0.2kg heating element took 5 seconds to heat from 20 °C to 100 °C. Calculate the specifi

Debora [2.8K]

Answer:

Specific heat capacity, c = 468.75 J/Kg°C

Explanation:

Given the following data;

Power = 1.5 kW to Watts = 1.5 * 1000 = 1500 Watts

Time = 5 seconds

Mass = 0.2 kg

Initial temperature = 20°C

Final temperature = 100°C

To find specific heat capacity;

First of all, we would have to determine the energy consumption of the kettle;

Energy = power * time

Energy = 1500 * 5

Energy = 7500 Joules

Next, we would calculate the specific heat capacity of water.

Heat capacity is given by the formula;

$Q = mcdt$

Where;

Q represents the heat capacity or quantity of heat.
m represents the mass of an object.
c represents the specific heat capacity of water.
dt represents the change in temperature.

dt = T2 - T1

dt = 100 - 20

dt = 80°C

Making c the subject of formula, we have;

$c = \frac {Q}{mdt}$

Substituting into the equation, we have;

$c = \frac {7500}{0.2*80}$

$c = \frac {7500}{16}$

Specific heat capacity, c = 468.75 J/Kg°C

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3 years ago