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3 years ago

Shane's 100-watt radio draws 7 amps of current on a 120-volt circuit. What is the resistance in the radio?

Engineering

1 answer:

Elis [28]3 years ago

7 0

Answer:

Resistance, R = 2.04 Ohms.

Explanation:

Given the following data;

Current = 7 amps

Circuit voltage = 120 Volts

Power = 100 Watts

To find the resistance;

First of all, we would calculate the potential difference (voltage level) used by the radio.

Power = current * voltage

100 = 7 * voltage

Voltage = 100/7

Voltage = 14.29 Volts

Next, we solve for the resistance of the radio;

Ohm's law states that at constant temperature, the current flowing in an electrical circuit is directly proportional to the voltage applied across the two points and inversely proportional to the resistance in the electrical circuit.

Mathematically, Ohm's law is given by the formula;

$V = IR$

Where;

V represents voltage measured in voltage.

I represents current measured in amperes.

R represents resistance measured in ohms.

Substituting into the formula, we have;

$14.29 = 7*R$

$R = \frac {14.29}{7}$

Resistance, R = 2.04 Ohms.

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A four-cylinder, four-stroke internal combustion engine operates at 2800 RPM. The processes within each cylinder are modeled as

marysya [2.9K]

Answer:

1) 287760.4 Hp

2) 18410899.5 kPa

Explanation:

The parameters given are;

p₁ = 14.7 lbf/in² = 101325.9 Pa

v₁ = 0.0196 ft³ = 0.00055501 m³

T₁ = 80°F = 299.8167 K

k = 1.4

Assumptions;

1) Air standard conditions are appropriate

2) There are negligible potential and kinetic energy changes

3) The air behaves as an ideal gas and has constant specific heat capacities of temperature and pressure

1) Process 1 to 2

Isentropic compression

T₂/T₁ = (v₁/v₂)^(1.4 - 1) = 10^0.4

p₂/p₁ = (v₁/v₂)^(1.4)

p₂ = p₁×10^0.4 = 101325.9*10^0.4 = 254519.153 Pa

T₂ = 299.8167*10^0.4 = 753.106 K

p₃ = 1080 lbf/in² = 7,446,338 Pa

Stage 2 to 3 is a constant volume process

p₃/T₃ = p₂/T₂

7,446,338/T₃ = 254519.153/753.106

T₃ = 7,446,338/(254519.153/753.106) = 22033.24 K

T₃/T₄ = (v₁/v₂)^(1.4 - 1) = 10^0.4

T₄ = 22033.24/(10^0.4) = 8771.59 K

The heat supplied, Q₁ = cv(T₃ - T₂) = 0.718*(22033.24 -753.106) = 15279.14 kJ

The heat rejected = cv(T₄ - T₁) = 0.718*(8771.59 - 299.8167) = 6082.73 kJ

W(net) = The heat supplied - The heat rejected = (15279.14 - 6082.73) = 9196.41 kJ

The power = W(net) × RPM/2*1/60 = 9196.41 * 2800/2*1/60 = 214582.9 kW

The power by the engine = 214582.9 kW = 287760.4 Hp

2) The mean effective pressure, MEP = W(net)/(v₁ - v₂)

v₁ = 0.00055501 m³

v₁/v₂ = 10

v₂ = v₁/10 = 0.00055501/10 = 0.000055501

MEP = 9196.41/(0.00055501 - 0.000055501) = 18410899.5 kPa

4 0

3 years ago

The device shown below contains 2 kg of water. The cylinder is allowed to fall 800 m during which the temperature of the water i

olganol [36]

Answer:

m_added = 2 kg

Explanation:

From the question, we are told that the cylinder is allowed to fall 800 m in height. Thus, the potential energy will be converted into heat energy which will increase the temperature of water .

Now, let the mass of the falling cylinder be denoted by "m1" and let h be the height of fall.

Thus;

Formula for potential energy = mgh

Thus, as said earlier it's converted to heat generated. So heat generated = m1gh

Now let's calculate the heat absorbed;

heat absorbed = (m2)cΔt

Where;

ΔT is change in temperature

c is specific heat of water .

m2 is mass of water

Heat absorbed = heat generated

Thus;

(m2)cΔt = m1gh

Δt = m1gh/(m2•c)

Now, in both cases of the water and cylinder, m1, g , h and c are constant

Thus, we have;

Δt = (m1gh/m2) × 1/c

Where;

(m1gh/m2) is denoted as a constant k.

Thus;

Δt = K/m

For the first experiment, we have;

m = 2 kg

Δt = 2.4

Thus;

2.4 = K/2

Multiply both sides by 2 to get;

K = 4.8

For the second experiment, we have;

Δt = 1.2

Also,we have seen that K = 4.8

Thus;

Δt = K/m

Thus;

1.2 = 4.8/m

m = 1.2

m = 4 kg

Thus,mass added is;

m_added = 4 - 2

m_added = 2 kg

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3 years ago

Describe the distribution of laminations used in the fabrication of a glulam member that is to be used principally as a bending

Mashcka [7]

Answer:

Glulam is an industrial wood product that optimizes the structural qualities of wood. These structural elements are composed of individual segments whose dimensions correspond to the natural wood from which they originate. These segments are joined at their ends for the production of longer elements, which are then glued with adhesives in order to create the required dimensions of the structural elements.

Explanation:

Thanks to its composition, larger glulam elements can be manufactured from smaller trees. Glulam offers builders and designers the strength and versatility of the structural elements of wood, but they would no longer depend on wood that comes from old trees.

Glulam has a higher stiffness than ordinary wood and is stronger than steel. This means that the structural elements of glulam have greater flexibility and can be used in the construction of homes or bridges.

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3 years ago

When will stemuless checks come I was told not to file my taxes because I get a pension check every month direct deposit money i

Keith_Richards [23]

The IRS and the U.S Department of the treasury declared that social security recipients are not required to file a simple tax return to receive stimulus payments under the CARES Act.

Explanation:

Due to the impact of corona virus problem, the CARES Act calls for stimulus payment to be sent to Americans based on their gross income.

The Social security recipients are not required to file a tax return and do not take action and they will receive the payments directly to their bank accounts.

The Automatic payments will begin by next week. The eligible taxpayers who filed tax returns for 2019 or 2018 and chose direct deposit for their refund will automatically receive a stimulus payment of $1,200 for individuals or $2,400 for married couples and $500 for each qualifying child.

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3 years ago

Which option identifies which design process should be used in the following scenario?

Rus_ich [418]

Answer:

I'm not sure about this

Explanation:

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