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3 years ago

The correct statement about the lift and drag on an object is:_______

Engineering

2 answers:

Lisa [10]3 years ago

8 0

Answer:

(a). the resultant force in the direction of the freestream velocity is termed the drag and the resultant force normal to the freestream velocity is termed the lift

Explanation:

When a fluid flows around the surface of an object, it exerts a force on it. This force has two components, namely lift and drag.

The component of this force that is perpendicular (normal) to the freestream velocity is known as lift, while the component of this force that is parallel or in the direction of the fluid freestream flow is known as drag.

Lift is as a result of pressure differences, while drag results from forces due to pressure distributions over the object surface, and forces due to skin friction or viscous force.

Thus, drag results from the combination of pressure and viscous forces while lift results only from the<em> pressure differences</em> (not pressure forces as was used in option D).

The only correct option left is "A"

(a). the resultant force in the direction of the freestream velocity is termed the drag and the resultant force normal to the freestream velocity is termed the lift

adoni [48]3 years ago

7 0

Answer:

Explanation:

I hope this helps! :)

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The chart shows the bids provided by four engineers to test a prototype.

klasskru [66]

Answer:

Explanation:

To know which is most or least cost-effective, it's not enough to look at only the per day rate, or only the time to complete. You have to multiply them to get the total cost of the project.

$\left[\begin{array}{ccccc}&Cost\ per\ day\ (\$)&Time\ to\ complete\ (days)&Total\ cost\ (\$)\\Zoe&500&8&4000\\Greg&650&10&6500\\Orion&400&12&4800\\Jin&700&5&3500\end{array}\right]$

As you can see, Greg is the least cost-effective because he charges the most for the project.

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3 years ago

Shows a closed tank holding air and oil to which is connected a U-tube mercury manometer and a pressure gage. Determine the read

damaskus [11]

Answer:

$P_2-P_1=27209h$

Explanation:

For pressure gage we can determine this by saying:

The closed tank with oil and air has a pressure of P₁ and the pressure of oil at a certain height in the U-tube on mercury is p₁gh₁. The pressure of mercury on the air in pressure gauge is p₂gh₂. The pressure of the gage is P₂.

$P_1+p_1gh_1=p_2_gh_2+P_2$

We want to work out P₁-P₂: Heights aren't given so we can solve it in terms of height: assuming h₁=h₂=h

$P_1-P_2=p_1gh_1-p_2gh_2=(55)\cdot{32.2}h-845\cdot{32.2}h$

$P_2-P_1=27209h$

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3 years ago

Jordan's dad made a new recipe for dinner. Jordan looked at the food and saw that it was white, yellow, and purple in color. She

zhenek [66]

Answer:

Jordan used her eyes to see the food, her touch to feel the food, and her nose to smell the food, and lastly, but most importantly, she used her mouth to taste the food.

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2 years ago

Viefleur [7K]

Answer:

Both come from the sun

Both are reusable sources

and both don't cause pollution

Explanation:

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2 years ago

A 20 kg mass is thrown from the ground to a height of 50 m. (a) find the kinetic energy of the mass at this height. (b) find the

horrorfan [7]

Answer:

(a) 0 kJ

(b) 9.81 kJ

Explanation:

(a)

From the law of conservation of energy, energy can only be transformed from one state to another. At a height of 50 m, all the kinetic energy is converted to potential energy hence KE=0

(b)

Potential energy, PE=mgh where m is the mass, g is acceleration due to gravity and h is the height

Substituting 50 m for h and 20 Kg for m, taking g as 9.81 then

PE=20*9.81*50=9810 J=9.81 kJ

(c)

Relating the equation of potential energy to the equation of kinetic energy, which is $0.5mv^{2}$