For a 20 ohm resistor R, the current i = 2 A. What is the voltage V? Submit your answer as a number without units.

At a certain location, wind is blowing steadily at 7 m/s. Determine the mechanical energy of air per unit mass and the power gen

Kaylis [27]

Answer:

Explanation:

From the information given;

The velocity of the wind blow V = 7 m/s

The diameter of the blades (d) = 80 m

Percentage of the overall efficiency $\eta_{overall} = 30\%$

The density of air $\rho = 1.25 kg/km^3$

Then, we can use the concept of the kinetic energy of the wind blowing to estimate the mechanic energy of air per unit mass by using the formula:

$e_{mechanic} = \dfrac{mV^2}{2}$

here;

m = $\rho AV$

= $1.25 \times \dfrac{\pi}{4}(80)^2 \times 7$

= 43982.29 kg/s

∴

$W = e_{mechanic} = \dfrac{mV^2}{2}$

$= \dfrac{43982.29 \times 7^2}{2}$

$= 1077566.105 \ W$

$\mathbf{ =1077.566 \ kW}$

The actual electric power is:

$W_{electric} = \eta_{overall} \times W$

$W_{electric} = 0.3 \times 1077.566$

$\mathbf{W_{electric} =323.26 \ kW}$

8 0

2 years ago

Carnot heat engine A operates between 20ºC and 520ºC. Carnot heat engine B operates between 20ºC and 820ºC. Which Carnot heat en

nikklg [1K]

Answer:

engine B is more efficient.

Explanation:

We know that Carnot cycle is an ideal cycle for all working heat engine.In Carnot cycle there are four processes in which two are constant temperature processes and others two are isentropic process.

We also kn ow that the efficiency of Carnot cycle given as follows

$\eta =1-\dfrac{T_1}{T_2}$

Here temperature should be in Kelvin.

For engine A

$\eta =1-\dfrac{T_1}{T_2}$

$\eta =1-\dfrac{273+20}{520+273}$

$\eta =0.63$

For engine B

$\eta =1-\dfrac{T_1}{T_2}$

$\eta =1-\dfrac{273+20}{820+273}$

$\eta =0.73$

So from above we can say that engine B is more efficient.

4 0

3 years ago

Determine the work input and entropy generation during the compression of steam from 100 kPa to 1 MPa in (a) an adiabatic pump a

Goshia [24]

Answer:

See attachment below

Explanation:

6 0

3 years ago

A new 1.2-ha suburban residential development is to be drained by a storm sewer that connects to the municipal drainage system.

valentinak56 [21]

Answer:

Time of concentration, $t_d$ ⇒ 1280 min

Peak runoff rate, $Q_p$ ⇒4.185 ff³/s

Explanation:

See detailed explanation

6 0

3 years ago

Discuss in detail the following methods used to redistribute income and wealth in cash grants?

aev [14]

Answer:

Redistribution of income and wealth is the transfer of income and wealth (including physical property) from some individuals to others through a social mechanism such as taxation, welfare, public services, land reform, monetary policies, confiscation, divorce or tort law.

-The term typically refers to redistribution on an economy-wide basis rather than between selected individuals.

Interpretations of the phrase vary, depending on personal perspectives, political ideologies and the selective use of statistics.

-It is frequently heard in politics, usually referring to perceived redistribution from those who have more to those who have less. Occasionally, however, it is used to describe laws or policies that cause opposite redistribution that shift monetary burdens from low-income earners to the wealthy.

-

The phrase is often coupled with the term class warfare, with high-income earners and the wealthy portrayed as victims of unfairness and discrimination.

-

Redistribution tax policy should not be confused with predistribution policies. "Predistribution" is the idea that the state should try to prevent inequalities from occurring in the first place rather than through the tax and benefits system once they have occurred. For example, a government predistribution policy might require employers to pay all employees a living wage, not just a minimum wage, as a "bottom-up" response to widespread income inequalities or high poverty rates.

Many alternate taxation proposals have been floated without the political will to alter the status quo. One example is the proposed "Buffett Rule", which is a hybrid taxation model composed of opposing systems, intended to minimize the favoritism of the special interest tax design.

7 0

3 years ago

For a 20 ohm resistor R, the current i = 2 A. What is the voltage V? Submit your answer as a number without units. ​

For a 20 ohm resistor R, the current i = 2 A. What is the voltage V? Submit your answer as a number without units.