Answer:
210,600πft-lb
Explanation:
Force is a function F(x) of position x then in moving from
x = a to x= b
Work done = [tex]\int\limits^b_a {Fx} \, dx[/tex]
Consider a water tank conical in shape
we will make small horizontal section of the water at depth h and thickness dh and also assume radius at depth h is w
we will have ,
[tex]\frac{w}{12} = \frac{(18-h)}{18} \\w = \frac{2}{3} (18-h)a[/tex]
weight of slice under construction
weight = volume × density × gravitational constant
[tex]weight = \pi \times w^2 \times dh \times 62.4\\= (62.4\pi w^2dh)lb[/tex]
Now we can find work done
[tex]W = \int\limits \, dw\\[/tex]
[tex]\int\limits^{18}_{3} {(62.4\pi } \, dx w^2dh)h\\= 62\pi \frac{4}{9} \int\limits^{18}_{3} {(18-h)^2hdh} \,[/tex]
= [tex]62.4\pi \times\frac{4}{9} (\frac{324}{2} h^2-\frac{36}{3} + \frac{h^4}{4})^1^8_3[/tex]
= 210,600πft-lb
A diver goes under water and measures the pressure. At some point his instruments read a pressure of 50,000 Pa. How deep did the diver go in meters? The density of water is 1000 kg/m^3. (Write the number only with 1 significant figure)
Answer:
[tex]y\approx 5\ m[/tex]
Explanation:
The pressure of a Fluid
A fluid of density [tex]\rho[/tex] exerts pressure at a distance y (deep) given by
[tex]P=\rho\cdot y\cdot g[/tex]
Where g is the acceleration of gravity or [tex]g=9.8\ m/s^2[/tex]
This formula computes the pressure assuming the initial pressure is 0 at fluid (water in this case) level.
Knowing the measured pressure, we can know how deep the diver went by solving the equation for y
[tex]\displaystyle y=\frac{P}{\rho\cdot g}[/tex]
Let's plug in the given values
[tex]P=50,000\ Pa= 50,000\ N/m^2[/tex]
[tex]\rho=1,000\ kg/m^3[/tex]
[tex]g=9.8\ m/s^2[/tex]
Thus
[tex]\displaystyle y=\frac{50,000\ N/m^2}{1,000\ kg/m^3\cdot 9.8\ m/s^2}[/tex]
[tex]y\approx 5\ m[/tex]
According to the Ideal Gas Law, , where P is pressure, V is volume, T is temperature (in Kelvins), and k is a constant of proportionality. A tank contains 2500 cubic inches of nitrogen at a pressure of 36 pounds per square inch and a temperature of 700 K. Write P as a function of V and T after evaluating k.
Answer:
P = 128.6 T / V
Explanation:
The ideal gas equation is
P V = n R T
Where the pressure is
P = 36 pounds / in²
V = 2500 in³
T = 700 K
PV = k T
k = PV / T
k = 36 2500/700
k = 128.6
P = 128.6 T / V
Find a unit vector in the direction in which f increases most rapidly at P and give the rate of chance of f in that direction; find a unit vector in the direction in which f decreases most rapidly at P and give the rate of change of f in that direction.
Answer:
Check attachment for complete question
Question
Find a unit vector in the direction in which
f increases most rapidly at P and give the rate of change of f
in that direction; Find a unit vector in the direction in which f
decreases most rapidly at P and give the rate of change of f in
that direction.
f (x, y, z) = x²z e^y + xz²; P(1, ln 2, 2).
Explanation:
The function, z = f(x, y,z), increases most rapidly at (a, b,c) in the
direction of the gradient and decreases
most rapidly in the opposite direction
Given that
F=x²ze^y+xz² at P(1, In2, 2)
1. F increases most rapidly in the positive direction of ∇f
∇f= df/dx i + df/dy j +df/dz k
∇f=(2xze^y+z²)i + (x²ze^y) j + (x²e^y + 2xz)k
At the point P(1, In2, 2)
Then,
∇f= (2×1×2×e^In2+2²)i +(1²×2×e^In2)j +(1²e^In2+2×1×2)
∇f=12i + 4j + 6k
Then, unit vector
V= ∇f/|∇f|
Then, |∇f|= √ 12²+4²+6²
|∇f|= 14
Then,
Unit vector
V=(12i+4j+6k)/14
V=6/7 i + 2/7 j + 3/7 k
This is the increasing unit vector
The rate of change of f at point P is.
|∇f|= √ 12²+4²+6²
|∇f|= 14
2. F increases most rapidly in the positive direction of -∇f
∇f=- (df/dx i + df/dy j +df/dz k)
∇f=-(2xze^y+z²)i - (x²ze^y) j - (x²e^y + 2xz)k
At the point P(1, In2, 2)
Then,
∇f= -(2×1×2×e^In2+2²)i -(1²×2×e^In2)j -(1²e^In2+2×1×2)
∇f=-12i -4j - 6k
Then, unit vector
V= -∇f/|∇f|
Then, |∇f|= √ 12²+4²+6²
|∇f|= 14
Then,
Unit vector
V=-(12i+4j+6k)/14
V= - 6/7 i - 2/7 j - 3/7 k
This is the increasing unit vector
The rate of change of f at point P is.
|∇f|= √ 12²+4²+6²
|∇f|= 14
There's a part of the question missing and it is:
f(x, y) = 4{x(^3)}{y^(2)} ; P(-1,1)
Answer:
A) Unit vector = 4(3i - 2j)/ (√13)
B) The rate of change;
|Δf(1, - 1)|= 4/(√13)
Explanation:
First of all, f increases rapidly in the positive direction of Δf(x, y)
Now;
[differentiation of the x item alone] to get;
fx(x, y) = 12{x(^2)}{y^(2)}
So at (1,-1), fx(x, y) = 12
Similarly, [differentiation of the y item alone] to get; fy(x, y) =
8{x(^3)}{y}
At (1,-1), fy(x, y) = - 8
Therefore, Δf(1, - 1) = 12i - 8j
Simplifying this, vector along gradient = 4(3i - 2j)
Unit vector = 4(3i - 2j)/ (√(3^2) + (-2^2) = 4(3i - 2j)/ (√13)
Therefore, the rate of change;
|Δf(1, - 1)|= 4/(√13)
green light in the visible portion of the electromagnetic radiation sepectrum has a wave length around 550nm.Express this wavelength in meters using exponential notation
The wavelength of green light in meters using exponential notation is 5.5 × 10-7 m.
Explanation:The green light in the visible portion of the electromagnetic radiation spectrum has a wavelength of around 550 nm (nanometers).
To express this wavelength in meters using exponential notation, we can convert nanometers to meters by dividing by 109. So, the wavelength of green light is 5.5 × 10-7 m (meters).
The electric field of a sinusoidal electromagnetic wave obeys the equation E = (360V/m) sin[ (6.00×1015rad/s)t + (1.96×107rad/m)x ]. What is the amplitude of the magnetic field of this wave? A) 0.06 μT B) 0.23 μT C) 1.10 μT D) 1.20 μT
Answer:
Option D is correct.
Explanation:
Bmax = Emax / c
The general form for electromagnetic wave equation is
E = jEmax ×cos(kx-wt)
We were given
(360V/m) sin[ (6.00×1015rad/s)t + (1.96×107rad/m)x ].
So from the equation above
Emax = 360V/m
Bmax = 360/(3×10⁸) = 1.2 ×10‐⁶ T.
Answer
Option D
Amplitude of Magnetic field = B = 1.2×10⁻⁶ T
Explanation:
The relationship between electric field and magnetic field of an electromagnetic wave is given by
B = E/c
Where B is the amplitude of magnetic field and E is the amplitude of electric field and c is the speed of light
The amplitude of electric field is given as 360 V/m
B = (360 V/m)/(3×10⁸ m/s)
B = 1.2×10⁻⁶ V.s/m²
Since 1 Tesla is equal to 1 V.s/m²
B = 1.2×10⁻⁶ T
Therefore, option D is correct
A current I = 20 A is directed along the positive x-axis and perpendicular to a magnetic field. A magnetic force per unit length of 0.16 N/m acts on the conductor in the negative y-direction. Calculate the magnitude and direction of the magnetic field in the region through which the current passes. magnitude T direction
Answer:
the magnitude and direction of the magnetic field in the region through which the current passes is 0.008 T and +z direction.
Explanation:
given information:
current, I = 20 A
magnetic force per unit length, F/L = 0.16 N/m
the conductor in the negative y-direction
θ = 90° (perpendicular)
as we know the formula to calculate magnetic force is
F = B I L sin θ
B = F/(I L sin θ)
= (F/L) (1/I sin θ)
= 0.16 (1/15 sin 90)
= 0.008 T
since F is in the negative y direction, based of the right hand rule the magnetic field is in positive z direction
Answer:
Explanation:
Given:
current, I = 20 A
Magnetic force per unit length, F/L
= 0.16 N/m
Conductor in the negative y-direction, therefore θ = 90° (perpendicular)
For a magnetic field,
F = B I L sin θ
B = F/(I L sin θ)
= 0.16 × (1/15 sin 90)
= 0.008 T
The field is in the +ve z - direction.