a car goes from a velocity zero to a velocity of 15 meters per second East in 2.1 seconds. What is the car's acceleration?

At a certain location, wind is blowing steadily at 9 m/s. Determine the mechanical energy of air per unit mass and the power gen

Misha Larkins [42]

Answer:

The specific mechanical energy of the air in the specific location is 40.5 J/kg.
The power generation potential of the wind turbine at such place is of 2290 kW
The actual electric power generation is 687 kW

Explanation:

The mechanical energy of the air per unit mass is the specific kinetic energy of the air that is calculated using: $\frac{1}{2} V^2$ where V is the velocity of the air.
The specific kinetic energy would be: $\frac{1}{2}(9\frac{m}{s})^2=40.5\frac{m^2}{s^2}=40.5\frac{m^2 }{s^2}\frac{kg}{kg}=40.5\frac{N*m }{kg}=40.5\frac{J}{kg}$ .
The power generation of the wind turbine would be obtained from the product of the mechanical energy of the air times the mass flow that moves the turbine.
To calculate mass flow it is required first to calculate the volumetric flow. To calculate the volumetric flow the next expression would be: $\frac{V\pi D_{blade}^2}{4} =\frac{9\frac{m}{s}\pi(80m)^2}{4} =45238.9\frac{m^3}{s}$
Then the mass flow is obtain from the volumetric flow times the density of the air: $m_{flow}=1.25\frac{kg}{m^3}45238.9\frac{m^3}{s}=56548.7\frac{kg}{s}$
Then, the Power generation potential is: $40.5\frac{J}{kg} 56548.7\frac{kg}{s} =2290221W=2290.2kW$
The actual electric power generation is calculated using the definition of efficiency: $\eta=\frac{E_P}{E_I}}$ , where η is the efficiency, $E_P$ is the energy actually produced and, $E_I$ is the energy input. Then solving for the energy produced: $E_P=\eta*E_I=0.30*2290kW=687kW$

6 0

2 years ago

I need help to figure out how to solve this problem and solve it!!!

wariber [46]

well it looks like the walk at a constant increasing pace then at a constant pace then increaseing pace then constant pace then they slow down then walk at a constant pace then walk at a constantly increasing pace

plz rate me brainliest

4 0

3 years ago

Read 2 more answers

The acclaimed environmental book, Silent Spring, was written by this woman in 1962.

olga_2 [115]

Rachel Carson was the author of the acclaimed environmental book, Silent Spring. The book was published in 1962.
It documented the negative effect that synthetic pesticides have on the environment, specifically on birds.
This book laid bare to the American public what chemical companies indirectly contributed to the environment.
The public furor this book caused led to the reversal of the national pesticide policy, a nationwide ban on DDT for agricultural uses, and inspired the creation of the U.S. Environmental Protection Agency.

7 0

2 years ago

The two cyclists travel at the same speed on level ground. They approach a low hill and decide to coast up instead of hard pedal

Sergeeva-Olga [200]

Answer:

<u>Option-(E): </u>Bike B; its wheels have a smaller moment of inertia.

Explanation:

The two cyclists travel at the same speed on level ground, as they approach a low hill and decide to coast up instead of hard pedaling. At the top of the hill, as bike "B" will have a larger speed, as compared to the bike "A".Due, to the effect of having smaller moment of inertia, I=m×r².

Having no friction nor air resistance, and all the wheels roll on the ground without slipping. While, the B have larger speed,v due to the fact that bike "B" will have a larger speed,"v" as compared to the bike "A".

3 0

2 years ago

What type of wave has particles push together and pull apart?

wariber [46]

when wave propagate through the medium the medium particles have two type of possible motions

1) Transverse Waves : here medium particles will move perpendicular to wave propagation and they pull and push perpendicular to the length

2) Longitudinal wave : here medium particles will move to and fro along the length of the medium and the medium particles will push and pull together along the length of the string.

So here in two types of wave motion it will depends on the medium type as well as it will depend on the source how is wave produced.

So the given type of wave in which particles push together and pull apart the wave must be longitudinal wave.

5 0

3 years ago