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3 years ago

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HELP!!! When fat comes in contact with sodium hydroxide, it produces soap and glycerin. Determine whether this is a physical cha

nge or a chemical change. Explain your answer.

1 answer:

dimaraw [331]3 years ago

5 0

Answer:it's a chemical change.physical changes occur without 2 or more reactants,a reaction,and a product

Explanation:

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The metal with the highest melting temperature is tungsten which melts at around 3400 K. What is the wavelength of the peak of t

alekssr [168]

Explanation:

It is given that, the metal with the highest melting temperature is tungsten which melts at around 3400 K, T = 3400 K

We need to find the wavelength of the peak of the black body distribution for this temperature. It can be calculated using Wein's displacement law as :

$\lambda\times T=k$

k is the constant, $k=2.89\times 10^{-3}\ m.k$

$\lambda=\dfrac{k}{T}$

$\lambda=\dfrac{2.89\times 10^{-3}\ m.k}{3400\ k}$

$\lambda=8.5\times 10^{-7}\ m$

or

$\lambda=850\ nm$

The wavelength of infrared is from 700 nm to 1 mm. So, the lies in infrared region of the spectrum. Hence, this is the required solution.

7 0

3 years ago

Which term describes the upward force that acts on an object submerged in a fluid?

MaRussiya [10]

The answer would be: buoyancy

6 0

3 years ago

Read 2 more answers

Thermal energy transfers from a cup of tea at 350 K to the hand holding it. <br> A)True<br> B)False

Alexandra [31]

Answer:

true

Explanation:

it is an energy transfer

6 0

2 years ago

A life preserver is thrown from an helicopter straight down to a person in distress. The initial velocity of the life preserver

Leno4ka [110]

Answer:29.627 m

Explanation:

Given

Initial velocity of life preserver(u) is 1.6 m/s

it takes 2.3 s to reach the water

using equation of motion

v=u+at

$v=1.6+9.81\times 2.3$

v=24.163 m/s

Let s be the height of life preserver

$v^2-u^2=2gs$

$24.163^2-1.6^2=2\times 9.81\times s$

$s=\frac{581.29}{2\times 9.81}$

s=29.627 m

6 0

3 years ago

Find the shear stress and the thickness of the boundary layer (a) at the center and (b) at the trailing edge of a smooth flat pl

melomori [17]

Answer:

a) The shear stress is 0.012

b) The shear stress is 0.0082

c) The total friction drag is 0.329 lbf

Explanation:

Given by the problem:

Length y plate = 2 ft

Width y plate = 10 ft

p = density = 1.938 slug/ft³

v = kinematic viscosity = 1.217x10⁻⁵ft²/s

Absolute viscosity = 2.359x10⁻⁵lbfs/ft²

a) The Reynold number is equal to:

$Re=\frac{1*3}{1.217x10^{-5} } =246507, laminar$

The boundary layer thickness is equal to:

$\delta=\frac{4.91*1}{Re^{0.5} } =\frac{4.91*1}{246507^{0.5} } =0.0098$ ft

The shear stress is equal to:

$\tau=0.332(\frac{2.359x10^{-5}*3 }{1} )(246507)^{0.5} =0.012$

b) If the railing edge is 2 ft, the Reynold number is:

$Re=\frac{2*3}{1.215x10^{-5} } =493015.6,laminar$

The boundary layer is equal to:

$\delta=\frac{4.91*2}{493015.6^{0.5} } =0.000019ft$

The sear stress is equal to:

$\tau=0.332(\frac{2.359x10^{-5}*3 }{2} )(493015.6^{0.5} )=0.0082$

c) The drag coefficient is equal to:

$C=\frac{1.328}{\sqrt{Re} } =\frac{1.328}{\sqrt{493015.6} } ==0.0019$

The friction drag is equal to:

$F=Cp\frac{v^{2} }{2} wL=0.0019*1.938*(\frac{3^{2} }{2} )(10*2)=0.329lbf$

7 0

3 years ago