Nêu đặc điểm của tín hiệu PAM rời rạc dạng lưỡng cực NRZ, RZ

An FPC 4 m2 in area is tested during the night to measure the overall heat loss coefficient. Water at 60 C circulates through th

sp2606 [1]

Answer:

<em> - 14.943 W/m^2K ( negative sign indicates cooling ) </em>

Explanation:

Given data:

Area of FPC = 4 m^2

temp of water = 60°C

flow rate = 0.06 l/s

ambient temperature = 8°C

exit temperature = 49°C

<u>Calculate the overall heat loss coefficient </u>

Note : heat lost by water = heat loss through convection

m*Cp*dT = h*A * ( T - To )

∴ dT / T - To = h*A / m*Cp ( integrate the relation )

In ( $\frac{49-8}{60-8}$ ) = h* 4 / ( 0.06 * 10^-3 * 1000 * 4180 )

In ( 41 / 52 ) = 0.0159*h

hence h = - 0.2376 / 0.0159

= - 14.943 W/m^2K ( heat loss coefficient )

7 0

2 years ago

Plssssssssssssss Alexi is writing a program which prompts users to enter their age. Which function should she use?

aleksandr82 [10.1K]

Answer:

int()

Explanation:

float() is using decimals, so that can't be it, like float(input( "how much does this cost?"))

print() is used to print something, not a user asking, like print("hello")

string() means like a whole, like string( I am good)

By elimination, int() is correct.

Hope this helps!

7 0

2 years ago

Assume the average fuel flow rate at the peak torque speed (1500 rpm) is 15kg/hr for a sixcylinder four-stroke diesel engine und

sveticcg [70]

Answer:

Q = 8.845 DEGREE

Explanation:

given data:

combine Mass for 6 cylinder (M) =15 Kg/hr

mass of each cylinder (m) = 15/6 = 2.5 Kg/hr = 0.000694 Kg/ sec

Engine speed (N)= 1500rpm

Diameter of one nozzle hole ( d) = 200 micrometer = 0.0002 m

Discharge Coefficient (Cd) = 0.75

Pressure difference = 100 MPa

Density of fuel = 800 kg/m^3

velocity of fuel is $v = cd\sqrt{\frac{2*P}{p}}$

$v = 0.75 \sqrt{\frac{2\times 100\times 10^6}{800}} = 375 m/sec$

injected fuel volume (V) =Area of given Orifices × Fuel velocity × time of single injection × no of injection/sec

we know that p = m/ V

So $V = \frac{0.000694}{800} =8.68\times10^{-7} m3/sec$

putting these value in volume equation and solve for Discharge $8.68\times 10^{-7} = (\frac{(3.14}{4})\times 6\times( .0002\times .0002) \times 375 \times \frac{(Q}{360}) \times \frac{30}{750} \times \frac{(750}{60)}$

Q = 8.845 DEGREE

4 0

3 years ago

You buy a 75-W lightbulb in Europe, where electricity is delivered to homes at 240V. If you use the lightbulb in the United Stat

givi [52]

Answer:

The bulb will be $\frac{1}{4}$ times as bright as it is in Europe.

Explanation:

Data provided in the question:

Power of bulb in Europe = 75 W

Voltage provided in Europe = 240 V

Voltage provided in United Stated = 120 V

Now,

We know,

Power = Voltage² ÷ Resistance

Therefore,

75 = 240² ÷ Resistance

or

Resistance = 240² ÷ 75

or

Resistance = 768 Ω

Therefore,

Power in United States = Voltage² ÷ Resistance

= 120² ÷ 768

= 18.75 W

Therefore,

Ratio of powers

$\frac{\text{Power in united states}}{\text{Power in Europe}}=\frac{18.75}{75}$

= $\frac{1}{4}$

Hence,

The bulb will be $\frac{1}{4}$ times as bright as it is in Europe.

7 0

3 years ago

Light from a helium-neon laser (λ = 633 nm) illuminates two slits spaced 0.50 mm apart. A viewing screen is 2.5 m behind the sli

serg [7]

Answer:

Explanation:

Given

wavelength $\lambda =633\ nm$

distance between two slits $d=0.5\ mm$

Screen is placed at a distance $L=2.5\ m$

Location of a (n+1)th bright fringe is given by

$x_{n+1}=\frac{L}{2d}(n+1)\lambda$

for nth bright fringe

$x_n=\frac{L}{2d}(n)\lambda$

Distance between two bright fringes

$x_{n+1}-x_n=\frac{L}{2d}\cdot \lambda$

$x_{n+1}-x_n=\frac{2.5}{2\times 0.5\times 10^{-3}}\cdot 633\times 10^{-3}$

$x_{n+1}-x_n=1.582\ mm$

7 0

3 years ago