Ask question

Ask question

All categories

2 years ago

7

The inner and outer surfaces of a 5m x 6m brick wall of thickness 30 cm and thermal conductivity 0.69 w/m.0 c are maintained at

temperature of 20 0 c and 50 c, respectively. determine the rate of heat transfer through the wall, in w.

1 answer:

Volgvan2 years ago

4 0

The working equation to be used here is written below:

Q = kA(T₁ - T₂)/Δx
where
Q is the rate of heat transfer
k is the heat transfer coefficient
A is the cross-sectional area of the wall
T₁ - T₂ is the temperature difference between the sides of the wall
Δx is the thickness of the wall

The solution is as follows:

Q = (0.69 W/m²·°C)(5 m × 6 m)(50°C - 20°C)/(30 cm * 1 m/100 cm)
Q = 2,070 W/m

You might be interested in

Pamela has three computers, all of

Fiesta28 [93]

U need to write better u egg head kid or tell your mom

5 0

1 year ago

Read 2 more answers

What is the final speed of an object that starts from rest and accelerates uniformly at 4.0 meters per second2 over a distance o

jonny [76]

Considering that the acceleration is uniform $a=4 (m/s^2)$ we apply the equation
$v^2=v0^2+2as$
with zero initial speed
$v^2=2as$
and we obtain the speed
$v^2 =2*8*4 =64 (m/s)^2$
Thus $v=8 (m/s)$

4 0

2 years ago

A lever has a 36cm input arm and a 6cm output arm. find MA.

Nady [450]

6

Explanation:

The mechanical advantage is a factor that measures how input force increases using a machine.

A lever is a simple machine with the fulcrum at the center.

To calculate the mechanical advantage M.A of levers we use the expression below;

M. A = $\frac{F_{b} }{F_{a} }$ = $\frac{a}{b}$

$F_{a}$ = input force

$F_{b}$ = output force

a is the distance of the input force from the fulcrum

b is the distance of the output force from the fulcrum

Given

a = 36cm

b = 6cm

M.A = $\frac{36cm}{6cm}$ = 6

learn more:

Torque brainly.com/question/5352966

#learnwithBrainly

6 0

2 years ago

Assume that the mass has been moving along its circular path for some time. You start timing its motion with a stopwatch when it

lesya692 [45]

Answer:

$v = R\omega(-sin\omega t \hat i + cos\omega t \hat j)$

Explanation:

As we know that the mass is revolving with constant angular speed in the circle of radius R

So we will have

$\theta = \omega t$

now the position vector at a given time is

$r = Rcos\theta \hat i + R sin\theta \hat j$

now the linear velocity is given as

$v = \frac{dr}{dt}$

$v = (-R sin\theta \hat i + R cos\theta \hat j)\frac{d\theta}{dt}$

$v = R\omega(-sin\omega t \hat i + cos\omega t \hat j)$

6 0

1 year ago

The diameters of bolts produced by a certain machine are normally distributed with a mean of 0.30 inches and a standard deviatio

enot [183]

Answer:

2.25 %

Explanation:

65-95-99.7 is a rule to remember the precentages that lies around the mean.

at the range of mean ( $\mu$ ) plus or minus one standard deviation ( $\sigma$ ), $P([\mu-\sigma \leq X \leq \mu+\sigma])\approx 68.3%$

at the range of mean plus or minus two standard deviation, $P([\mu -2\sigma \leq X \leq \mu+2\sigma])\approx 95.5%$

at the range of mean plus or minus three standard deviation, $P([\mu - 3\sigma\leq X \leq \mu+3\sigma])\approx 99.7%$

So, note that they are asking about the probability that it is greater than 0.32, that is the mean (0.3) plus two times the standard deviation (0.1) ( $P(X \leq \mu+2\sigma)$ )

So we know that the 95.5% is between $\mu - 2\sigma = 0.3 -2*0.1 = 0.28$ and $\mu + 2\sigma = 0.3 +2*0.1 = 0.32$ , hence approximately the 4.5% (100%-95.5%) is greater than 0.32 or less than 0.28. But half (4.5%/2=2.25%) is greater than 0.32 and the other half is less than 0.28.

So $P(X \leq \mu+2\sigma) \approx 2.25%$

8 0

1 year ago