A kite is an airfoil that uses the wind to produce a lift. Held in place by a string, a kite can remain aloft indefinitely. The
diamond kite is a particularly simple kite. As the wind passes under the lower surface of the diamond kite, it bends away from the surface and slows down. The air pressure under the lower surface is
1 answer:
Answer:
<em>a) results in an increased pressure.</em>
<em>b) results in a pressure lower than the atmospheric pressure.</em>
<em>c) The direction of the overall force is upwards.</em>
<em>d) other forces are the weight, drag, and tension on the string.</em>
<em>e) the extra weight due to the tail adds drag and keeps the nose of the kite pointing upwards and the kite generally stable.</em>
<em></em>
Explanation:
a) As the wind passes under the lower surface of the diamond kite, it slows down. The slowing down of the wind under the lower surface results in an increased air pressure under the lower surface which now exceeds the pressure at the upper surface of the diamond kite, generating more lift upwards.
b) As the wind passes over the upper surface of the diamond kite, turbulence occurs resulting in pressure lower than the atmospheric pressure. This results in a reduce air drag on the kite.
c) The direction of the overall force exerted by the air on the kite is upwards.
d) Other force that acts on the kite in the air are; gravity force (due to the weight of the kite), drag (due to air flow around the kite), and tension force on the string from you. Once at the maximum height, the approximate net force on the kite is zero (provided the kite is stable at this height).
e) The extra weight of the kite due to the tail adds drag at the bottom of the kite, keeping the nose pointing upwards, and keeps the kite stable.
You might be interested in
Answer:
The volume of the gas is 11.2 L.
Explanation:
Initially, we have:
V₁ = 700.0 L
P₁ = 760.0 mmHg = 1 atm
T₁ = 100.0 °C
When the gas is in the thank we have:
V₂ =?
P₂ = 20.0 atm
T₂ = 32.0 °C
Now, we can find the volume of the gas in the thank by using the Ideal Gas Law:
(1)
Where R is the gas constant
With the initials conditions we can find the number of moles:
(2)
By entering equation (2) into (1) we have:
Therefore, When the gas is placed into a tank the volume of the gas is 11.2 L.
I hope it helps you!
Answer:
a) 75%
b) 82%
Explanation:
Assumptions:
Properties: The density of water
Conversions:
Analysis:
Note that the bottom of the lake is the reference level. The potential energy of water at the surface becomes gh. Consider that kinetic energy of water at the lake surface & the turbine exit is negligible and the pressure at both locations is the atmospheric pressure and change in the mechanical energy of water between lake surface & turbine exit are:
Then;
gh = 0.491 kJ/kg
= 1559 kW
Therefore; the overall efficiency is:
= 0.75
= 75%
b) mechanical efficiency of the turbine:
thus;