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>
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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.
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Answer:
A) 11.1 ms
B) 5.62 Ω
Explanation:
L ( inductance ) = 10 mH
Vcc = 14V
<u>A) determine the required on time of the switch such that the peak energy stored in the inductor is 1.2J </u>
first calculate for the current ( i ) using the equation for energy stored in an inductor hence
i = ----- ( 1 )
where : W = 1.2j , L = 10 mH
Input values into equation 1
i = 15.49 A
Now determine the time required with expression below
i( t ) = 15.49 A
L = 10 mH, Vcc = 14
hence the time required ( T-on ) = 11.1 ms
attached below is detailed solution
B) <u>select the value of R such that switching cycle can be repeated every 20 ms </u>
using the expression below
τ = ---- ( 2 )
but first we will determine the value of τ
τ = t-off / 5 time constants
= (20 - 11.1 ) / 5 = 1.78 ms
Back to equation 2
R = L / τ
= (10 * 10^-3) / (1.78 * 10^-3)
= 5.62 Ω
To solve this problem we will apply the concepts related to Soderberg's relation, which will allow us to find the safety factor based on yield stress, endurance strength, the mean and average stress. The mean and average stress values can be found through the alternating Stress previously given. We will proceed by defining the known values, that is
Yield stress
Endurance strength
The two values for alternating stress are
We know that mean stress is
And the average stress is
According to Soderberg relation
Therefore the factor of safety is 2
Answer:
Sedimentation is not a good method.
Explanation:
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So,
Replacing the values,
Here then we calculate the time,
Where x= Distance, v= velocity
To calculate the surface required we need first to calculate the volume through the volume,
So,
Then,
Here we can calculate the surface
<em>So, the requeriment of Area of tank and settlement time is huge, it's not a practical method.</em>