Answer:
Quantity of heat needed (Q) = 722.753 × 10³
Step-by-step explanation:
According to question,
Mass of water (m) = 40 kg
Change in temperature ( ΔT) = 18°c
specific heat capacity of water = 4200 j kg^-1 k^-1
The specific heat capacity is the amount of heat required to change the temperature of 1 kg of substance to 1 degree celcius or 1 kelvin .
So, Heat (Q) = m×s×ΔT
Or, Q = 40 kg × 4200 × 18
or, Q = 3024 × 10³ joule
Hence, Quantity of heat needed (Q) = 3024 × 10³ joule
In calories 4.184 joule = 1 calorie
So, 3024 × 10³ joule = 722.753 × 10³
Answer:
Step-by-step explanation:
A system of linear equations is one which may be written in the form
a11x1 + a12x2 + · · · + a1nxn = b1 (1)
a21x1 + a22x2 + · · · + a2nxn = b2 (2)
.
am1x1 + am2x2 + · · · + amnxn = bm (m)
Here, all of the coefficients aij and all of the right hand sides bi are assumed to be known constants. All of the
xi
’s are assumed to be unknowns, that we are to solve for. Note that every left hand side is a sum of terms of
the form constant × x
Solving Linear Systems of Equations
We now introduce, by way of several examples, the systematic procedure for solving systems of linear
equations.
Here is a system of three equations in three unknowns.
x1+ x2 + x3 = 4 (1)
x1+ 2x2 + 3x3 = 9 (2)
2x1+ 3x2 + x3 = 7 (3)
We can reduce the system down to two equations in two unknowns by using the first equation to solve for x1
in terms of x2 and x3
x1 = 4 − x2 − x3 (1’)
1
and substituting this solution into the remaining two equations
(2) (4 − x2 − x3) + 2x2+3x3 = 9 =⇒ x2+2x3 = 5
(3) 2(4 − x2 − x3) + 3x2+ x3 = 7 =⇒ x2− x3 = −1
Answer: A) 
B) H = 5.10
C) Yes
Step-by-step explanation: <u>Exponential</u> <u>Decay</u> <u>function</u> is a model that describes the reducing of an amount by a constant rate over time. Generally, it is written in the form: 
A) C is initial quantity, in this case, the initial concentration of DDT. To determine r, using the data given:



Using a natural logarithm property called <em>power rule:</em>



The decay function for concentration of DDT through the years is 
B) The value of H is calculated by 


Again, using power rule for logarithm:



H = 5.10
Constant H in the half-life formula is H=5.10
C) Using model
to determine concentration of DDT in 1995:

y(24) = 0.5
By 1995, the concentration of DDT is 0.5 ppm, so using this model is possible to reduce such amount and more of DDT.
Answer:
y=17
Step-by-step explanation:
So the shape is a square, which means 1 is equal to 90 degrees. So, 4y+22=90
When you solve, you get 17:
4y=68
y=17
Answer:
y = 3x - 12
Step-by-step explanation: