Fluid systems can distribute pressure unequally to all points in a system.<br><br> True<br> False

An LED camping headlamp can run for 18 hours, powered by three AAA batteries. The batteries each have a capacity of 1000 mAh, an

KIM [24]

Answer:

a) the power consumption of the LEDs is 0.25 watt

b) the LEDs drew 0.0555 Amp current

Explanation:

Given the data in the question;

Three AAA Batteries;

<---- 1000mAh [ + -] 1.5 v ------1000mAh [ + -] 1.5 v --------1000mAh [ + -] 1.5 v------

so V_total = 3 × 1.5 = 4.5V

a) the power consumption of the LEDs

I_battery = 1000 mAh / 18hrs { for 18 hrs}

I_battery = 1/18 Amp { delivery by battery}

so consumption by led = I × V_total

we substitute

⇒ 1/18 × 4.5

P = 0.25 watt

Therefore the power consumption of the LEDs is 0.25 watt

b) How much current do the LEDs draw

I_Draw = I_battery = 1/18 Amp = 0.0555 Amp

Therefore the LEDs drew 0.0555 Amp current

5 0

2 years ago

The production process of rods from machine "A" yields specimen with the following specs. Mean: µ(LA)=20.00mm, STD: s(LA)=0.50mm

Oxana [17]

Answer: the standard deviation STD of machine B is s (Lb) = 0.4557

Explanation:

from the given data, machine A and machine B produce half of the rods

Lt = 0.5La + 0.5Lb

so

s² (Lt) = 0.5²s²(La) + 0.5²s²(Lb) + 0.5²(2)Cov (La, Lb)

but Cov (La, Lb) = Corr(La, Lb) s(La) s(Lb) = 0.4s (La) s(Lb)

so we substitute

s²(Lt) = 0.25s² (La) + 0.25s² (Lb) + 0.4s (La) s(Lb)

0.4² = 0.25 (0.5²) + 0.25s² (Lb) + (0.5)0.4(0.5) s(Lb)

0.64 = 0.25 + s²(Lb) + 0.4s(Lb)

s²(Lb) + 0.4s(Lb) - 0.39 = 0

s(Lb) = { -0.4 ± √(0.16 + (4*0.39)) } / 2

s (Lb) = 0.4557

therefore the standard deviation STD of machine B is s (Lb) = 0.4557

8 0

2 years ago

In a team, a person’s efforts are less identifiable than when that person works independently. Because the person’s efforts are

Eduardwww [97]

The answer is deindividuation - a psychological state in which a person does not feel individual responsibility.

3 0

3 years ago

Which of the following statements best describes the relationship between availability of new green building products and custom

Fed [463]

Answer:

c

Explanation:

4 0

3 years ago

If you measured a pressure difference of 50 mm of mercury across a pitot tube placed in a wind tunnel with 200 mm diameter, what

mart [117]

Answer:

V=33.66 m/s

$Re=448.8\times 10^6$

Re>4000, The flow is turbulent flow.

Explanation:

Given that

Pressure difference = 50 mm of Hg

We know that density of Hg=136000 $Kg/m^3$

ΔP= 13.6 x 1000 x 0.05 Pa

ΔP=680 Pa

Diameter of tunnel = 200 mm

Property of air at 25°C

ρ=1.2 $Kg/m^3$

Dynamic viscosity

$\mu =1.8\times 10^{-8}\ Pa.s$

Velocity of fluid given as

$V=\sqrt{\dfrac{2\Delta P}{\rho_{air}}}$

$V=\sqrt{\dfrac{2\times 680}{1.2}}$

V=33.66 m/s

Reynolds number

$Re=\dfrac{\rho _{air}Vd}{\mu }$

$Re=\dfrac{1.2\times 33.66\times 0.2}{1.8\times 10^{-8}}$

$Re=448.8\times 10^6$

Re>4000,So the flow is turbulent flow.

4 0

3 years ago

Fluid systems can distribute pressure unequally to all points in a system. True False