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
Answer:
combining scientific knowledge, careful reasoning, and artistic invention in a flexible approach to problem-solving
Explanation:
Answer: Advertising acts in a method similar to a fee. People who watch TV broadcasts must watch ADs. TV stations turn this into money by selling airtime to advertisers.
Explanation:
A non-rival good is a good whose consumption by one person does not reduce the remaining quantity available. An example is a street light.
For non-excludable goods, it is impossible to prevent everyone from enjoying the benefits of the good. An example is a lighthouse. This is where the free rider problem comes in.
A free rider is someone enjoying the benefits of a good without paying for it. When a good is both non-rival and non-excludable, it is convenient for consumers to enjoy the benefit without paying for it.
If TV broadcasts are both non-rival and non-excludable, everybody can choose to become a free rider. Advertising can solve this problem by converting free riders to potential buyers of goods or services advertised during broadcasts. This way, stations can generate revenue by selling airtime.