Why is it important to keep hand tools free of oil and grease?

The heat flux through a 1-mm thick layer of skin is 1.05 x 104 W/m2. The temperature at the inside surface is 37°C and the tempe

miss Akunina [59]

Answer:

a) Thermal conductivity of skin: $k_{skin}=1.5W/mK$

b) Temperature of interface: $T_{interface}=35.6\°C$

Heat flux through skin: $\frac{Q}{A}=2100W/m^2$

Explanation:

a)

$k=\frac{QL}{A(T_{2}-T_{1})}$

Where: $k$ is thermal conductivity of a material, $\frac{Q}{A}$ is heat flux through a material, $L$ is the thickness of the material, $T_{1}$ is the temperature on the first side and $T_{2}$ is the temperature on the second side

$k_{skin}=\frac{QL}{A(T_{2}-T_{1})}$

$k_{skin}=\frac{Q}{A}*\frac{L}{(T_{2}-T_{1})}$

$k_{skin}=1.05*10^{4}*\frac{1*10^{-3}}{(37-30)}$

$k_{skin}=1.5W/mK$

b)

$k_{insulation}=\frac{k_{skin}}{2}$

$k_{insulation}=\frac{1.5}{2}$

$k_{insulation}=0.75W/mK$

The heat flux between both surfaces is constant, assuming the temperature is maintained at each surface.

$\frac{Q}{A}=\frac{k(T_{2}-T_{1})}{L}$

$\frac{k_{skin}(T_{skin}-T_{interface})}{L_{skin}}=\frac{k_{insulation}(T_{interface}-T_{insulation})}{L_{insulation}}$

$\frac{1.5*(37-T_{interface})}{0.001}=\frac{0.75*(T_{interface}-30)}{0.002}$

$55500-1500T_{interface}=375T_{interface}-11250$

$1875T_{interface}=66750$

$T_{interface}=35.6\°C$

$\frac{Q}{A}=\frac{k_{skin}(T_{skin}-T_{interface})}{L_{skin}}$

$\frac{Q}{A}=\frac{1.5*(37-35.6)}{0.001}$

$\frac{Q}{A}=2100W/m^2$

3 0

3 years ago

A customer asks why rogue has a vc-turbo engine when turbo engines are for sports cars. What are two ways to respond?.

aniked [119]

Best-in-class gas engine 1 and torque 2 fuel economy and All-new engine to be assembled at Nissan's powertrain facility in Decherd, Tenn.

<h3>Rogue</h3>

Nissan has introduced an all-new Rogue for the 2021 model year, delivering high quality and customer satisfaction through its strong combination of design, safety and technology. Now, for 2022, Nissan is making its best-selling model more powerful, more fuel efficient and more fun to drive with a new 1.5-liter Variable Compression (VC) Turbo engine across the Rogue lineup.

With this information, we can conclude that the vc-turbo engine is a great advance for fuel economy.

Learn more about Nissan in brainly.com/question/24814294

7 0

3 years ago

When was the first black or white hole discovered?

ivolga24 [154]

Answer:

1964

Explanation:

It was discovered in 1964 when a pair of Geiger counters were carried on board a sub-orbital rocket launched from New Mexico.

3 0

3 years ago

Later in this course we will learn how to combine flip-flops to make transitions to desired outputs. The flip-flop is holding bi

expeople1 [14]

Answer:

Clock input( or Timer Oscillator) in used to change the state of the output.

Explanation:

Flip-flop is an device that is the state changes with the rising or falling of the clock. It has a control signal (clock) input that stores the input state and outputs the state only in response to the clock signal.

The output changes with the change in the input in synchronization with the clock.

Whenever the input of the clock changed, it will result in change in the output.

8 0

3 years ago

I) A sag vertical curve is to be designed to join a 4% grade to a 2% grade. If the design

Burka [1]

Answer:

=4/5 because I'm not going to go back in a year meaning that they are you are

4 0

2 years ago