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
Answer:

Explanation:
Assume that the distance travelled initially is d.
In order to stop the block you need some external force which is friction.
If we use the law of energy conservation:

a)
Looking at the formula you can see that the mass doesn't affect the distance travelled, as lng as the initial velocity is constant (Which indicates that the force must be higher to push the block to the same speed) therefore the distance is the same.
b) If the velocity is doubled, then the distance travelled is multiplied by 4, because the distance deppends on the square of the velocity.
Answer:
with right hand grip rule
3. A- south
B- north
C- north
D- south
E- south
F- north
sorry idk what 1st & 2nd question means
Answer:
kinetic and potential energy). The opposite is true when you remove thermal energy: Particles move slower (less kinetic energy). Particles get closer together (less potential energy)
Total resistance = voltage / current = 220 / 5 = 44 ohms .
Even one 176-ohm resistor is too much. The current through it is 1.25 A,
and more than one of them in series reduces the current even further.
Connecting them in <em><u>parallel</u></em>, however . . .
Four resistors of 176-ohms each, in <u>parallel</u>, have a net effective resistance
of 176/4 = 44 ohms ... exactly what you need to do the job.