Answer:
4.8°C
Explanation:
The rate of heat transfer through the wall is given by:


Assumptions:
1) the system is at equilibrium
2) the heat transfer from foam side to interface and interface to block side is equal. There is no heat retention at any point
3) the external surface of the wall (concrete block side) is large enough that all heat is dissipated and there is no increase in temperature of the air on that side






temperature at the interface
Solving for
will give the temperature at the interface:





150
A
Explanation:
V
s
V
p
=
N
s
N
p
(
1
)
N
refers to the number of turns
V
is voltage
s
and
p
refer to the secondary and primary coil.
From the conservation of energy we get:
V
p
I
p
=
V
s
I
s
(
2
)
From
(
1
)
:
V
s
V
p
=
900
00
3
00
=
300
∴
V
s
=
300
V
p
Substituting for
V
s
into
(
2
)
⇒
V
p
I
p
=
300
V
p
×
0.5
∴
I
p
=
150
A
Seems a big current.
Answer:
It is important to inspect and check materials and tools for defects and damage before receiving them so that you can ask for replacements for those that you found .
Explanation:
Answer:
(a). the resultant force in the direction of the freestream velocity is termed the drag and the resultant force normal to the freestream velocity is termed the lift
Explanation:
When a fluid flows around the surface of an object, it exerts a force on it. This force has two components, namely lift and drag.
The component of this force that is perpendicular (normal) to the freestream velocity is known as lift, while the component of this force that is parallel or in the direction of the fluid freestream flow is known as drag.
Lift is as a result of pressure differences, while drag results from forces due to pressure distributions over the object surface, and forces due to skin friction or viscous force.
Thus, drag results from the combination of pressure and viscous forces while lift results only from the<em> pressure differences</em> (not pressure forces as was used in option D).
The only correct option left is "A"
(a). the resultant force in the direction of the freestream velocity is termed the drag and the resultant force normal to the freestream velocity is termed the lift