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Makovka662 [10]

3 years ago

7

- Viscoelastic stress relaxation

1 answer:

My name is Ann [436]3 years ago

5 0

Explanation:

The correct answers to the fill in the blanks would be;

1. Viscoelastic stress relaxation refers to scenarios for which the stress applied to a polymer must decay over time in order to maintain a constant strain. Otherwise, over time, the polymer chains will slip and slide past one another in response to a constant applied load and the strain will increase (in magnitude).

2. Viscoelastic creep refers to scenarios for which a polymer will permanently flow over time in response a constant applied stress.

The polymer whose properties have been mentioned above is commonly known as Kevlar.

It is mostly used in high-strength fabrics and its properties are because of several hydrogen bonds between polymer molecules.

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Four eight-ohm speakers are connected in parallel to an audio power amplifier. The amplifier can supply a maximum driver output

Vera_Pavlovna [14]

Answer:

112.5 watts

Explanation:

The output voltage (V) = 15 volts

The equivalent resistance for the speakers connected in parallel ( $R_T$ ) is gotten by using the formula:

$\frac{1}{R_T}=\frac{1}{R_1}+\frac{1}{R_2}+\frac{1}{R_3}+\frac{1}{R_4}\\\\But\ R_1=R_2=R_3=R_4=8\ ohm\\\\\frac{1}{R_T} =\frac{1}{8} +\frac{1}{8} +\frac{1}{8} +\frac{1}{8} \\\\\frac{1}{R_T} =\frac{1+1+1+1}{8} \\\\\frac{1}{R_T} =\frac{4}{8} \\\\R_T=\frac{8}{4} \\\\R_T=2\ ohm$

The current flowing through the amplifier (I) is:

I = V / $R_T$ = 15 / 2 = 7.5 A

The audio power (P) when outputting this maximum voltage is given by:

P = V² / $R_T$ = I² $R_T$ . Therefore:

P = V² / $R_T$ = 15² / $R_T$ = 112.5 watts

6 0

3 years ago

This acronym is a reminder of the most common types of hazards or injuries caused by electricity.

yulyashka [42]

Answer:

BE SAFE

Explanation:

it stands for Burns, Electrocution, Shock, Arch Flash/Arc Blast, Fire, Explosions

3 0

3 years ago

सत्य से अधिक उपयोगी एवं आज्ञापालन से श्रेष्ठ क्या है ?<br>answer fast plz

PilotLPTM [1.2K]

Answer:

I hope this helps you

Explanation:

किसी की जान बचाने के लिए झूठ बोलना सत्य से अधिक उपयोगी है । अन्यायपूर्ण आज्ञा का विरोध आज्ञापालन से श्रेष्ठ है ।

5 0

3 years ago

A power company desires to use groundwater from a hot spring to power a heat engine. If the groundwater is at 95 deg C and the a

prisoha [69]

Answer:

W = 12.8 KW

Explanation:

given data:

mass flow rate = 0.2 kg/s

Engine recieve heat from ground water at 95 degree ( 368 K) and reject that heat to atmosphere at 20 degree (293K)

we know that maximum possible efficiency is given as

$\eta = 1- \frac{T_L}{T_H}$

$\eta = 1 - \frac{ 293}{368}$

$\eta = 0.2038$

rate of heat transfer is given as

$Q_H = \dot m C_p \Delta T$

$Q_H = 0.2 * 4.18 8(95 - 20)$

$Q_H = 62.7 kW$

Maximuim power is given as

$W = \eta Q_H$

W = 0.2038 * 62.7

W = 12.8 KW

3 0

3 years ago

A rectangular open box, 25 ft by 10 ft in plan and 12 ft deep weighs 40 tons. Sufficient amount of stones is placed in the box a

dimulka [17.4K]

Answer:

44.95 tonnes

Explanation:

According to principle of buoyancy the object will just sink when it's weight is more than the weight of the liquid it displaces

It is given that empty weight of box = 40 tons

Let the mass of the stones to be placed be = M tonnes

Thus the combined mass of box and stones = (40+M) tonnes..........(i)

Since the box will displace water equal to it's volume V we have $volume of box = 25ft*10ft*12ft= 3000ft^{3}$

$Volume= 84.95m^{3}$

$Since 1ft^{3} =0.028m^{3}$

Now the weight of water displaced = $Weight =\rho \times Volumewhererho$ is density of water = 1000kg/ $m^{3}$

Thus weight of liquid displaced = $\frac{84.95X1000}{1000}tonnes=84.95 tonnes$ ..................(ii)

Equating i and ii we get

40 + M = 84.95

thus Mass of stones = 44.95 tonnes

3 0

3 years ago