This is very good conceptual question and can clear your doubts regarding work-energy theorem.
Whenever force is perpendicular to the direction of the motion, work done by that force is zero.
According to work-energy theorem,
Work done by all the force = change in kinetic energy.
here, work done = 0.
Therefore,
0=change in kinetic energy
This means kinetic energy remains constant.
Hope this helps
Answer:
Using the new cylinder the heat rate between the reservoirs would be 50 W
Explanation:
- Conduction could be described by the Law of Fourierin the form:
where
is the rate of heat transferred by conduction,
is the thermal conductivity of the material,
and
are the temperatures of each heat deposit,
is the cross area to the flow of heat, and
is the distance that the flow of heat has to go. - For the original cylinder the Fourier's law would be:
, and if
, then the expression would be:
where
is the diameter of the original cylinder, and
is the length of the original cylinder. - For the new cylinder, in the same fashion that for the first, Fourier's Law would be:
,where
is the heat rate in the second case,
and
are the new diameter and length. - But,
and
, substituting in the expression for
:
. - Rearranging:
. - In the last declaration of
, it could be noted that the expressión inside the parenthesis is actually
, then:
. - <u>It should be noted, that the temperatures in the hot and cold reservoirs never change.</u>
Answer:
I1 = 0.772 A
Explanation:
<u>Given</u>: R1 = 5.0 ohm, R2 = 9.0 ohm, R3 = 4.0 ohm, V = 6.0 Volts
<u>To find</u>: current I = ? A
<u>Solution: </u>
Ohm's law V= I R
⇒ I = V / R
In order to find R (total) we first find R (p) fro parallel combination. so
1 / R (p) = 1 / R1 + 1/ R2 ∴(P) stand for parallel
R (p) = R1R2 / ( R1 + R2)
R (p) = (5.0 × 9.0) / (5.0 + 9.0)
R (p) = 3.214 ohm
Now R (total) = R (p) + R3 (as R3 is connected in series)
R (total) = 3.214 ohm + 4.0 Ohm
R (total) = 7.214 ohm
now I (total) = 7.214 ohm / 6.0 Volts
I (total) = 1.202 A
This the total current supplied by 6 volts battery.
as voltage drop across R (p) = V = R (p) × I (total)
V (p) = 3.214 ohm × 1.202 A = 3.864 volts
Now current through 5 ohms resister is I1 = V (P) / R1
I1 = 3.864 volts / 5 ohm
I1 = 0.772 A