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photoshop1234 [79]

3 years ago

14

You work in a materials testing lab and your boss tells you to increase the temperature of a sample by 37.1 ∘c . the only thermo

meter you can find at your workbench reads in degrees fahrenheit.

1 answer:

Ivahew [28]3 years ago

7 0

Each Celsius degree is the size of 1.8 Fahrenheit degrees. So you need dip your Fahrenheit thermometer into the sample, see where you're starting, and then warm it up to a temperature that reads (37.1 x 1.8) = 66.8 Fahreheit degrees higher.

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A soccer player practices kicking the ball into the goal from halfway down the soccer field. The time it takes for the ball to g

12345 [234]

This is correct, I just did the test. Yes, displacement is 45 meters, elapsed time is three seconds, and the direction is toward the goal.

4 0

3 years ago

Read 2 more answers

efrigerant-134a is expanded isentropically from 600 kPa and 70°C at the inlet of a steady-flow turbine to 100 kPa at the outlet.

PolarNik [594]

Answer:

Inlet : $v_i=0.0646\frac{m}{s}$

Outlet: $v_o=0.171\frac{m}{s}$

Explanation:

1) Notation and important concepts

Flow of mass represent "the mass of a substance which passes per unit of time".

Flow rate represent "a measure of the volume of liquid that moves in a certain amount of time"

Specific volume is "the ratio of the substance's volume to its mass. It is the reciprocal of density."

Isentropic process is a "thermodynamic process, in which the entropy of the fluid or gas remains constant".

We know that the flow of mass is given by the following expression

$\dot{m}=\frac{\dot{V}}{\upsilon}$ , where $\dot{V}$ represent the flow rate and $\upsilon$ the specific volume at the pressure and temperature given.

$A_i=0.5m^2$ is the inlet area

$P_i=600Kpa$ pressure at the inlet area

$T_i=70C$ temperature at the inlet area

$A_o=1m^2$ is the outlet area

$P_o=100Kpa$ pressure at the outlet area

$T_o=C$ temperature at the outlet area

$\dot{m}=0.75\frac{kg}{s}$ represent the flow of mass

If we look at the first figure attached Table A-13 we see that the specific volume for the inlet condition is

$\upsilon_i =0.04304\frac{kg}{m^3}$ and the entropy is $h_i=1.0645\frac{KJ}{KgK}=h_o$

With the value of entropy and the outlet pressure of 100 Kpa we can find we specific volume at the outlet condition since w ehave the entropy $h_o=1.0645\frac{KJ}{KgK}$

Since on the table we don't have the exact value we need to interpolate between these two values (see the second figure attached)

$h_1=1.0531\frac{KJ}{KgK} , \upsilon_1=0.22473\frac{kg}{m^3}$

$h_2=1.0829\frac{KJ}{KgK} , \upsilon_2=0.23349\frac{kg}{m^3}$

Our interest value would be given using interpolation like this:

$\upsilon=0.22473+\frac{(0.23349-0.22473)}{(1.0829-1.0531)}(1.0645-1.0531)=0.228\frac{kg}{m^3}$

2) Solution to the problem

Now since we have all the info required to solve the problem we can find the velocities on this way.

We know from the definition of flow of mass that $\dot{m}=\frac{\dot{V}}{\upsilon}$ , but since $\dot{V}=Av$ we have this:

$\dot{m}=\frac{Av}{\upsilon}$

If we solve from the velocity v we have this:

$v=\frac{\upsilon \dot{m}}{A}$ (*)

And now we just need to replace the values into equation (*)

For the inlet case:

$v_i=\frac{\upsilon_i \dot{m}}{A_i}=\frac{0.043069\frac{kg}{m^3}(0.75\frac{kg}{s})}{0.5m^2}=0.0646\frac{m}{s}$

For the oulet case:

$v_o=\frac{\upsilon_o \dot{m}}{A_o}=\frac{0.228\frac{kg}{m^3}(0.75\frac{kg}{s})}{1m^2}=0.171\frac{m}{s}$

7 0

3 years ago

Why are eight electrons (four pairs) surrounding each non-hydrogen atom the optimal electronic arrangement for covalent molecule

rodikova [14]

Eight electrons surrounding each non-hydrogen atom is the optimal electronic arrangement for covalent molecules because it is needed to achieve an octet structure and is necessary to fill both the s and p subshells of electrons.

<h3>What is Covalent bonding?</h3>

This is the type of bonding which involves the sharing of electrons between atoms of an element.

This is done to achieve an octet configuration thereby making them stable and less reactive thereby making it the most appropriate choice.

Read more about Covalent bonding here brainly.com/question/3447218

#SPJ4

3 0

2 years ago

A father pushes his child on a swing. He pushes with a force of 20 N or a distance of 1 m, with the force always maintained para

Firlakuza [10]

Answer:

20 Joules

Explanation:

Work is done whenever a force moves a body through a certain distance in the direction of the force. So, work done is the product of force and distance moved.

Therefore, we have;

Work done = Force x distance

i.e Wd = Fs

Given that: F = 20 N and s = 1 m, then;

Wd = 20 N x 1 m

= 20 Nm

The work done by the father is 20 Joules(Nm).

7 0

3 years ago

When the wedges are removed, the cars will move. Predict which direction they will move and when they will stop

Neko [114]

Answer: hello your question lacks the required diagram attached below is the required diagram

answer : Both cars will move backwards and stop due to friction.

Explanation:

Given that both cars are negatively charged, When the wedges are removed both cars will move backwards ( repelling each other ) because they are like poles, and Like poles repel each other. while unlike poles attract each other ( forward movement ) .

The cars will later come to a stop due to frictional forces between the cars and the surface.

6 0

3 years ago