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A straight fin is made from copper (k = 388 W/m-K) and is 0.5 cm in diameter and 30 cm long. The temperature at the base of the

erastovalidia [21]

Answer:

The rate of transfer of heat is 0.119 W

Solution:

As per the question:

Diameter of the fin, D = 0.5 cm = 0.005 m

Length of the fin, l =30 cm = 0.3 m

Base temperature, $T_{b} = 75^{\circ}C$

Air temperature, $T_{infty} = 20^{\circ}$

k = 388 W/mK

h = $20\ W/m^{2}K$

Now,

Perimeter of the fin, p = $\pi D = 0.005\pi \ m$

Cross-sectional area of the fin, A = $\frac{\pi}{4}D^{2}$

A = $\frac{\pi}{4}(0.5\times 10^{-2})^{2} = 6.25\times 10^{- 6}\pi \ m^{2}$

To calculate the heat transfer rate:

$Q_{f} = \sqrt{hkpA}tanh(ml)(T_{b} - T_{infty})$

where

$m = \sqrt{\frac{hp}{kA}} = \sqrt{\frac{20\times 0.005\pi}{388\times 6.25\times 10^{- 6}\pi}} = 41.237$

Now,

$Q_{f} = \sqrt{20\times 388\times 0.005\pi\times 6.25\times 10^{- 6}\pi}tanh(41.237\times 0.3)(75 - 20) = 0.119\ W$

5 0

3 years ago

Which describes the average velocity of an ant traveling at a constant speed

yanalaym [24]

Answer: A. The total displacement divided by the time and C. The slope of the ant's displacement vs. time graph.

Explanation:

Hi! The question seems incomplete, but I found the options on the internt:

A. The total displacement divided by the time.

B. The slope of the ant's acceleration vs. time graph.

C. The slope of the ant's displacement vs. time graph.

D. The average acceleration divided by the time.

Now, since we know the ant is travelling at a constant speed, its average velocity $V$ will be expressed by the following equation:

$V=\frac{d}{t}$

Where:

$d$ is the ant's total displacement

$t$ is the time it took to the ant to travel to the kitchen

Hence one of the correct options is: A. The total displacement divided by the time

On the other hand, this can be expressed by a displacement vs. time graph graph, where the slope of that line leads to the equation written above. So, the other correct option is: C. The slope of the ant's displacement vs. time graph.

3 0

3 years ago

Scalars are used to solve projectile motion problems because they allow the analysis of one direction at a time for two-dimensio

Korolek [52]

The statement is false. Vectors are used to solve projectile motion problems because they allow the analysis of one direction at a time for two-dimensional motion. Scalar quantities can be used to analyze linear motion problem, but not projectile motion.

4 0

3 years ago

You are on roller blades on top of a small hill. Your potential energy is equal to 1,000.0 joules. The last time

irinina [24]

It is -59 i think or just ask someone esle for help

8 0

3 years ago

The proportion of carbon-14 in an organism is useful in figuring out the age of that organism after it dies because...?

nata0808 [166]

I believe the correct answer from the choices listed above is option D. The proportion of carbon-14 in an organism is useful in figuring out the age of that organism after it dies because <span>the proportion of carbon-14 slowly decreases after the death of the organism. Hope this answers the question.</span>

4 0

3 years ago

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