the answer in my opinion would be A
Answer:
b) True. the force of air drag on him is equal to his weight.
Explanation:
Let us propose the solution of the problem in order to analyze the given statements.
The problem must be solved with Newton's second law.
When he jumps off the plane
fr - w = ma
Where the friction force has some form of type.
fr = G v + H v²
Let's replace
(G v + H v²) - mg = m dv / dt
We can see that the friction force increases as the speed increases
At the equilibrium point
fr - w = 0
fr = mg
(G v + H v2) = mg
For low speeds the quadratic depended is not important, so we can reduce the equation to
G v = mg
v = mg / G
This is the terminal speed.
Now let's analyze the claims
a) False is g between the friction force constant
b) True.
c) False. It is equal to the weight
d) False. In the terminal speed the acceleration is zero
e) False. The friction force is equal to the weight
Answer:
The solution to the question above is explained below:
Explanation:
For which solid is the lumped system analysis more likely to be applicable?
<u>Answer</u>
The lumped system analysis is more likely to be applicable for the body cooled naturally.
<em>Question :Why?</em>
<u>Answer</u>
Biot number is proportional to the convection heat transfer coefficient, and it is proportional to the air velocity. When Biot no is less than 0.1 in the case of natural convection, then lumped analysis can be applied.
<u>Further explanations:</u>
Heat is a form of energy.
Heat transfer describes the flow of heat across the boundary of a system due to temperature differences and the subsequent temperature distribution and changes. There are three different ways the heat can transfer: conduction, convection, or radiation.
Heat transfer analysis which utilizes this idealization is known as the lumped system analysis.
The Biot number is a criterion dimensionless quantity used in heat transfer calculations which gives a direct indication of the relative importance of conduction and convection in determining the temperature history of a body being heated or cooled by convection at its surface. In heat transfer analysis, some bodies are observed to behave like a "lump" whose entire body temperature remains essentially uniform at all times during a heat transfer process.
Conduction is the transfer of energy in the form of heat or electricity from one atom to another within an object and conduction of heat occurs when molecules increase in temperature.
Convection is a transfer of heat by the movement of a fluid. Convection occurs within liquids and gases between areas of different temperature.
The force on the object has a constant strength, but its direction
keeps changing. The force is always directed from the object to
the center of the circle. It's called "centripetal force".
