All categories

3 years ago

Sandwich materials typically use a high density core with non-structural cover plates. a)True b)- False

Engineering

1 answer:

Lorico [155]3 years ago

4 0

Answer: False

Explanation: Sandwich materials are usually in composite material form which has a fabrication of two thin layers which are stiff in nature and have light weighing and thick core .The construction is based on the ratio that is of stiffness to the weight .Therefore, the density of the material in the core is not high and are only connected with the skin layer through adhesive .So the given statement is false that sandwich materials typically use a high density core with non- structural cover plates.

You might be interested in

Wind blows on the side of a fully enclosed hospital located on open flat terrain where V= 120 mi/h. Determine the external press

ss7ja [257]

Answer:

The external pressure is p = -21.9 psf or p = -8.85 psf

Explanation:

Given :

Velocity of wind, v = 120 mi / hr

$k_d = k_c =1$ (wind direction factor)

$k _{zt} = 1$ = topographical factor (for flat terrain)

$q_n$ = velocity pressure at height h

$\therefore q_n = 0.00256 k_z k_{zt} k_d v^2$

$q_n = 0.00256 \times k_z (1)(1)(120)^2$

$= 36.86 k_z$

But for height h = 30 ft, $k_z$ = 0.98 (from table)

$\therefore q_n = 36.86 \times 0.98$

= 36.16

Now, $\frac{L}{B}= \frac{200}{200} =1$ , so $C_p=-0.5$ (from table)

$p = q(G)(C_p)-q_n(GC_{pi})$

where, p = external pressure

G = 0.85 = gust factor (for typical rigid building)

$GC_{pi} = \pm 0.18$ (internal pressure co efficient)

Therefore putting the values,

$p = (36.13)(0.85)(-0.5)-(36.13)(\pm 0.18)$

p = -21.9 psf or p = -8.85 psf

4 0

4 years ago

A source current of 10 mA is supplied to a parallel circuit consisting of the following resistors three resistors, a 2200 a 500

marysya [2.9K]

It’s is 2000 because it is 20000

7 0

3 years ago

A rigid, insulated tank that is initially evacuated is connected through a valve to a supply line that carries helium at 200 kPa

Aleks04 [339]

Answer: a 8143.71 kJ/kg

b 393.15 K

Explanation:

This system is an isobaric process in which there is no change in pressure a quasistatic process where a pressure distribution exists

a since no change in pressure =0 the system does work thus

FOR HELIUM properties in standard thermodynamic chart

cv = 3.1 kJ/kgK

M = Molar mass = 4 kg/kmol

R = Universal gas constant = 8.314 kJ/kg K

cp ≈ cv +R /M = 3.1 + 8.314 /4 = 5.1785 kJ/kgK

Cp = cp * M = 5.1785 kJ/kgK * 4 kg/kmol = 20.714 kJ/kgkmol

T = 120 °C to Kelvin = 120 + 273.15k = 393.15 K

W =n Cp ΔT = 1 kmol * 20.714 kJ/kg kmol* 393.15 K = 8143.71 kJ/kg

b convert T °C = T K thus 120 + 273.15 K = 393.15 K

P₁/T₁ = P₂/T₂

200 kPa/ 393.15 K = 200 kPa/T₂

T₂ = 200 kPa * 393.15 K/ 200 kPa = 393.15 K or 120 k

7 0

4 years ago

A race car is travelling around a circular track. The velocity of the car is 20 m/s, the radius of the track is 300 m, and the m

Zielflug [23.3K]

Answer:

μ = 0.136

Explanation:

given,

velocity of the car = 20 m/s

radius of the track = 300 m

mass of the car = 2000 kg

centrifugal force

$F_c = \dfrac{mv^2}{r}$

$F_c = \dfrac{2000\times 20^2}{300}$

F c = 2666. 67 N

F f= μ N

F f = μ m g

2666.67 = μ × 2000 × 9.8

μ = 0.136

so, the minimum coefficient of friction between road surface and car tyre is equal to μ = 0.136

5 0

4 years ago

[ 3/8-28 UNC] According to the thread note, what does 3/8 mean?

lara [203]

Answer:

It diameter

Explanation:

That where the diameter always is.

4 0

3 years ago