Answer:
Q = - 4312 W = - 4.312 KW
Explanation:
The rate of heat of the concrete slab can be calculated through Fourier's Law of heat conduction. The formula of the Fourier's Law of heat conduction is as follows:
Q = - kA dt/dx
Integrating from one side of the slab to other along the thickness dimension, we get:
Q = - kA(T₂ - T₁)/L
Q = kA(T₁ - T₂)/t
where,
Q = Rate of Heat Loss = ?
k = thermal conductivity = 1.4 W/m.k
A = Surface Area = (11 m)(8 m) = 88 m²
T₁ = Temperature of Bottom Surface = 10°C
T₂ = Temperature of Top Surface = 17° C
t = Thickness of Slab = 0.2 m
Therefore,
Q = (1.4 W/m.k)(88 m²)(10°C - 17°C)/0.2 m
<u>Q = - 4312 W = - 4.312 KW</u>
<u>Here, negative sign shows the loss of heat.</u>
The complete question is: A student draws a picture of the products and reactants of a chemical reaction. What, if anything, is wrong with the drawing?
A) The drawing is wrong because there are more chemicals on the products side.
B) The drawing is correct because there are 12 compounds on each side of the arrow.
C) The drawing is wrong because there are different compounds on each side of the arrow.
D) The drawing is correct because there are 12 atoms of each type on each side of the arrow.
Answer:
Option D is correct
Explanation:
In the diagram attached below, it can be seen that there are 12 atoms of element which combine with 12 atoms of another element forming a compound. For the drawing to be correct, there should be 12 atoms of each type of element on both the reactants as well as product side, which is the case. There cannot be imbalance in the number of atoms of different elements on the two sides for a chemical reaction to occur.
Hence, option D is correct.
#16
If we put a resistor in circuit it will slow the speed of current
Let's check ohms law

- So if resistance is more current is less
#17
Again use ohms law


- Voltage must be increased
Answer:
The magnetic flux density is 
Explanation:
Given that,
Distance = 0.36 m
Current = 3.8 A
We need to calculate the magnetic flux density
Using formula of magnetic field

Where,
r = radius
I = current
Put the value into the formula


Hence, The magnetic flux density is 
Answer:
b
Explanation:
friction needs two objects
the two objects need to touch each other
the two objects need to either have relative movement or, tend to have relative movement urge. (kinetic friction or static friction)