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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 pressure differences (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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Which of the following statements most accurately describes the circuit?

Fofino [41]

Answer:

Explanation:

All of the above.

7 0

3 years ago

Calculate the biaxial stresses σ1 and σ2 for the biaxial stress case, where ε1 = .0020 and ε2 = –.0010 are determined experiment

Llana [10]

Answer:

i) σ1 = 133.5 MPa

σ2 = -2427 MPa

ii) 78.89 MPa

Explanation:

Given data:

ε1 = 0.0020 and ε2 = –0.0010

E = 71 GPa

v = 0.35

i) Determine the biaxial stresses σ1 and σ2 using the relations below

ε1 = σ1 / E - v (σ2 / E) -----( 1 )

ε2 = σ2 / E - v (σ1 / E) -------( 2 )

resolving equations 1 and 2

σ1 = E / 1 - v^2 { ε1 + vε2 } ---- ( 3 )

σ2 = E / 1 - v^2 { ε2 + vε1 } ----- ( 4 )

input the given data into equation 3 and equation 4

σ1 = 133.5 MPa

σ2 = -2427 MPa

ii) Calculate the value of the maximum shear stress ( Zmax )

Zmax = ( σ1 - σ2 ) / 2

= 133.5 - ( - 2427 ) / 2

= 78.89 MPa

3 0

3 years ago

calculate how much black eyes seeds are necessary to plant a 6- hectare( 14.425 acres) field. given that the weight of 1000 blac

11111nata11111 [884]

Answer: 1.38g

Explanation:

Width of planting area = 100m

Field size = 6-hectares(14.425 acres)

Weight of 1000 black eye seed = 230g

1 lb = 453.4g

1 black eye seed = 230g/1000 = 0.23g = 0.00023kg

1 hectare = 10,000sq metre

6 hectare = 60,000sq metre

(Weight/Area) kg/m2

0.00023kg / 10,000 = 2.3×10^-8kg/m^2

And field size = 6hectares = 60,000m^2

(2.3×10^-8) × 60,000 = 0.00138kg of black eye seed

0.00138kg × 1000 = 1.38g

6 0

3 years ago

The roof of a house has three layers: (1) 2 inch thick pine, (2) 4 inches of fiberglass insulation and (3) 0.1 inch thick Asphal

Alex17521 [72]

Answer:

the rate of flow of heat through the roof is 45616.858 BTU/hr

Explanation:

Given the data in the question;

pin thickness $t_p$ = 2 in

fiber glass thickness $t_f$ = 4 in

Asphalt shingles thickness $t_a$ = 0.1 in

R/inch for pine = 1.28

R/inch for fiberglass = 3.0

R/inch for Shingles = 4.0

Temperature inside the house $T_{inside$ = 700 F

Temperature outside the house $T_{outside$ = 300 F

area of the roof A = 500 ft²

we calculate the total Resistance;

R = ( 2 × 1.28 ) + ( 4 × 3.0 ) + ( 0.1 × 4.0 )

R = 2.56 + 12 + 0.4

R = 14.96

Now, we determine the rate of heat flow;

dQ/dt = ΔT(A) / R

⇒ ( $T_{inside$ - $T_{outside$ )A / R

we substitute

⇒ (( 700 - 300 ) × 500 ) / 14.96

⇒ ( 400 × 500 ) / 14.96

⇒ 200000 / 14.96

⇒ 13368.98 watt

we know that 1 watt = 3.412142 BTU/hr

⇒ ( 13368.98 × 3.412142 ) BTU/hr

⇒ 45616.858 BTU/hr

Therefore, the rate of flow of heat through the roof is 45616.858 BTU/hr

6 0

3 years ago

Problem 1: Experts on hypothermia tell us that heat loss from the body is much greater in 10°C water than in air at the same tem

pochemuha

Answer:

See explaination

Explanation:

Please see attachment for the step by step solution of the given problem .

It is very detailed in the file attached.

4 0

2 years ago