Answer:
<em>UP</em>
Explanation:
heat flows from higher level to lower level
( higher concentration to lower concentration )
and since temperature in above block is less than the lower block, the heat will flow from lower block to higher block .
( Up )
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.
<span>by vectors that are all the same length
</span>
Answer:
3.486 km
Explanation:
Suppose Joe and Max's directions are perfectly perpendicular (east vs north). We can calculate their distance at the destinations using Pythagorean theorem:
where J = 0.5 km and M= 3.45 km are the distances between Joe and Max to their original parting point, respectively. s is the distance between them.
Answer:
the current flowing in each is the same.
Explanation:
When resistors are connected in series, they are connected in the same branch of the circuit - this means that the same current flows through each resistor.
The other options listed are wrong because:
the same power is dissipated in each one --> false: the power dissipated in each resistor is 
, where I is the current and R the resistance, so it depends on the value of the resistance
the potential difference across each is the same.-- > false: this is true in parallel circuits, not series circuits
the equivalent resistance of the circuit is less than that of the smallest resistor.--> false: the equivalent resistance of a series circuit is the sum of the individual resistances: 
, so it is larger than the resistance of the smallest resistance
the equivalent resistance of the circuit is equal to the average of all the resistances. --> false: the equivalent resistance of a series circuit is the sum of the individual resistances: , not the average
