If there is no friction, the force that moves the box forward horizontally must be matched by the same force.
If there is friction, then the force moving it forward = frictional force + the additional force you need to add.
I think the correct answer from the choices listed above is option D. Scientific theories summarize patterns found in nature. Although, the statement scientific theories are never proven is somewhat true. They are either disproved or they are never disproved. Hope this answers the question.
Answer:
Given that
D= 4 mm
K = 160 W/m-K
h=h = 220 W/m²-K
ηf = 0.65
We know that
For circular fin
m = 37.08
By solving above equation we get
L= 36.18 mm
The effectiveness for circular fin given as
ε = 23.52
<span>The characteristic not observed is the sun and planets rotate in the same direction. The planets in the solar system go around the sun. The sun is in a fixed position relative to planets. The time one planet takes to go around the sun is a year on that planet. the suns gravity keeps the solar system together and th planets revolving aroud it </span>
