Answer:
Yes it is important.
Explanation:
It is important because we should preserve our food with safety as we would take it in the next day so if we we will not take safety then many germs can enter in that food and if we eat that food we could get sick . If we keep the food uncovered so anything can happen like any insect can fall in the food and we didn't know it it or any germs can enter in the food that is very harmful for our body so so we should keep the food covered and well preserved.
Physics question 28 plz help me
Answer:
a. I = 30 A
b. E = 1080000 J = 1080 KJ
c. ΔT = 12.86°C
d. Cost = $ 4.32
Explanation:
a.
The current in the coil is given by Ohm's Law:
[tex]V = IR\\I = \frac{V}{R}[/tex]
where,
I = current = ?
V = Voltage = 120 V
R = Resistance = 4 Ω
Therefore,
[tex]I = \frac{120\ V}{4 \Omega}\\[/tex]
I = 30 A
b.
The energy can be calculated as:
[tex]E = VIt\\E = (120\ V)(30\ A)(5\ min)(\frac{60\ s}{1\ min})\\[/tex]
E = 1080000 J = 1080 KJ
c.
For the increase in the temperature of water:
[tex]E = mC\Delta T\\[/tex]
where,
m = mass of water = 20 kg
C = specific heat of water = 4.2 KJ/kg.°C
Therefore,
[tex]1080\ KJ = (20\ kg)(4.2\ KJ/kg.^oC)\Delta T[/tex]
ΔT = 12.86°C
d.
First, we will calculate the total energy consumed:
[tex]E=(Power)(Time)\\E=VI(Time)\\E = (120\ V)(30\ A)(0.5\ h/d)(30\ d)\\E = 54000\ Wh\\E = 54 KWh[/tex]
Now, for the cost:
[tex]Cost = (Unit\ Cost)(Energy)\\Cost = (\$ 0.08\KWh)(54\ KWh)[/tex]
Cost = $ 4.32
Charge of uniform density (40 pC/m2) is distributed on a spherical surface (radius = 1.0 cm), and a second concentric spherical surface (radius = 3.0 cm) carries a uniform charge density of 60 pC/m2. What is the magnitude of the electric field at a point 2.0 cm from the center of the two surfaces?
Answer:
E = K Q / R^2 by Gauss' Law where Q is the charge enclosed by the surface of revolution and R is the distance from the enclosed charge
Since Q = d 4 pi r^2 where d is the charge density and r the radius of the inner sphere
E = K / R^2 * (4 d pi r^2) = 4 K pi d (r / R)^2 = 4 K pi d * 1/4
E = 9 * 10E9 * 3.14 * 40 * 10E-12 = 1.13 N / C
Tritium (hydrogen-3) undergoes radioactive decay to produce helium-3. Which
particle needs to be added to this equation to show that the total numbers of
neutrons and protons are not changed by the reaction?
H He + ?
O A. He
O B. He
O c., e
O D.,
An electron particle needs to be added to this equation to show that the total number of neutrons and protons is not changed by the reaction.
Explain the tritium decay?Tritium has nearly the same chemical characteristics as regular hydrogen. It produces helium-3 by releasing a beta particle and decaying with a half-life of 12 years.
Tritium breaks down into helium by producing a beta particle. The discharge of radiation during this decay process raises questions regarding tritium's and other radioactive compounds' safety.
The radiation produced by tritium decay is in the form of low-energy beta particles.
The chemical equation representation during the tritium decay is;
₁H³→₂He³+₋₁e⁰
The particle needs to be added to this equation to show that the total number of neutrons and protons are not changed by the reaction will be an electron.
Hence option D is correct.
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After graduation, you face a choice. You can work for a multinational consulting firm and earn a starting salary (including benefits) of $40,000, or you can start your own consulting firm using $5,000 of your own savings. If you keep your money in a savings account, you can earn an interest rate of 7 percent. You choose to start your own consulting firm. At the end of the first year, you add up all of your expenses and revenues. Your expenses include $14,000 for rent, $1,000 for office supplies, $24,000 for labor, and $4,500 for telephone expenses. After operating your consulting firm for a year, your total revenues are $88,000.
Required:
What are your total explicit cost and total implicit costs?
Answer:
Explanation:
Money is used to cover the explicit cost. They're what we're used to seeing, and they're easy to identify. There are several classifications for explicit costs; we can distinguish between fixed and variable costs, as well as direct and indirect costs. Raw materials, manpower, indirect production costs, and so on are all factors that contribute to its expense.
The opportunity cost of using a resource is the amount of money paying for it that might have been used on something else.
Alternative benefit options or money that we miss earning by doing such business acts are referred to as opportunity costs.
When a corporation foregoes an alternative action but does not make a bill, it incurs implicit costs. These are a company's hidden costs:
1. The use of the firm's own funds (money or assets).
2. The owner's capital, savings, and financial services are used.
From the given information:
The total explicit cost = Rent + office supplies + office staff + telephone expense
=$( 14000 + 1000 + 24000 + 4500)
= $43500
The total implicit cost = forgone salary + forgone interest
= $40000 + 7% of $5000
= $40000 + 350
=$40350
An open organ pipe emits E (330 Hz ) when the temperature is 26 ∘C. The speed of sound in air is v≈(331+0.60T)m/s, where T is the temperature in ∘C. Determine the length of the pipe.
Answer:
0.525 m
Explanation:
From the question,
In an open pipe,
v = λf................... Equation 1
Where v = speed of sound in the pipe, f = frequency, λ = wave length.
But,
λ = 2l................ Equation 2
Where l = length of the pipe
Substitute equation 2 into equation 1
v = 2lf.............. Equation 3
make l the subject of the equation
l = v/2f............. Equation 4
Given:
v ≈ (331+0.60T) m/s at T = 26°C
v ≈ (331+0.60×26) ≈ 346.6 m/s
f = 330 Hz.
Substitute these values into equation 4
l = 346.6/(2×330)
l = 346.6/660
l = 0.525 m
Hence the length of the pipe is 0.525 m
Find the current passing through each of the 3 resistors connected parallel to each other as shown in the figure (i1, i2, I3). Show your actions clearly.
Answer:
I1 = ε/R1
I2 = ε/R2
I3 = ε/R3
Explanation:
From the image, we see that the resistors are connected in parallel. This means that the voltage passing through them is the same.
Now, formula for current is; I = V/R
In this case, V which is voltage is denoted by ε.
Thus;
I1 = ε/R1
I2 = ε/R2
I3 = ε/R3
In the process of changing a flat tire, a motorist uses a hydraulic jack. She begins by applying a force of 58 N to the input piston, which has a radius r1. As a result, the output plunger, which has a radius r2, applies a force to the car. The ratio r2/r1 has a value of 8.2. Ignore the height difference between the input piston and output plunger and determine the force that the output plunger applies to the car.
Answer:
The correct answer is "3899.92 N".
Explanation:
The given values are:
Force,
[tex]F_{app}=58 N[/tex]
Ratio,
[tex]\frac{R_2}{R_1}=8.2[/tex]
As we know,
Area, [tex]A=\pi r^2[/tex]
or,
⇒ [tex]\frac{F_2}{F_1} =\frac{A_2}{A_1}[/tex]
On substituting the value of "A", we get
⇒ [tex]\frac{F_2}{F_1} =\frac{\pi r_2^2}{\pi r_1^2}[/tex]
⇒ [tex]\frac{F_2}{F_1} =\frac{r_2^2}{r_1^2}[/tex]
On applying cross-multiplication, we get
⇒ [tex]F_2=F_1\times (\frac{r_2}{r_1} )^2[/tex]
On substituting the given values, we get
⇒ [tex]=58\times (8.2)^2[/tex]
⇒ [tex]=58\times 67.2[/tex]
⇒ [tex]=3899.92 \ N[/tex]
BRAINLIEST PLEASE HELP ASAP DO NOT ANSWER UNLESS YOU KNOW AND DON'T GIVE ME A LINK OR I WILL REPORT YOU
1. Explain what type of lever is a baseball bat and why the bat is that type of lever in relation to the input force, output force, and fulcrum.
2. Explain for which class of lever is the output force always greater than the input force.
3. Explain for which class of lever is the output force always less than the input force.
4. Use the law of conservation of energy to explain why in a second class lever the distance over which the input force is applied is always greater than the distance over which the output force is applied.
5. A lever has an IMA of 4. If the length of the length of the input arm is 1.0 meter, what is the length of the output arm.
Answer:
In a third class lever, the effort is located between the load and the fulcrum. ... If the fulcrum is closer to the effort, then the load will move a greater distance. A pair of tweezers, swinging a baseball bat or using your arm to lift something are examples of third class levers.
Explanation:
Using a Boltzmann distribution, find the fraction of atoms in the excited state versus the ground state (i.e. the relative population) in a plasma source and a flame source. Assume that the lowest energy of a sodium atom lies at 3.371x10-19 J above the ground state, the degeneracy of the excited state is 2, whereas that of the ground state is 1, and the temperature of the flame is 3000 K and 10,000 K for plasma.
Answer:
0.174 plasma
[tex]$5.85 \times 10^{-4}$[/tex] flame
Explanation:
Given :
Energy :
[tex]$\Delta E=3.371 \times 10^{-19} $[/tex] J per atom
[tex]$g^*=2$[/tex] (degenraci of excited state)
g = 1 (degenraci of excited state)
Boltzmann Distribution
[tex]$\frac{N^*}{N}=\frac{g^*}{g}e^{-\frac{\Delta E}{kT}}$[/tex]
where,
[tex]$N^*$[/tex] = atoms in excited state
N = atoms in lower energy level
k = [tex]$1.38 \times 10^{-23}$[/tex] J/K
Therefore,
Relative population in plasma
T = 10,000 K
[tex]$\frac{N^*}{N}=\frac{g^*}{g}e^{-\frac{\Delta E}{kT}}$[/tex]
[tex]$\frac{N^*}{N}=\frac{2}{1}e^{-\frac{-3.37\times 10^{-19}}{1.38 \times 10^{-23} \times 10000}}$[/tex]
[tex]$\frac{N^*}{N}=2 \times e^{-2.44275}$[/tex]
[tex]$\frac{N^*}{N}=2 \times 0.8692$[/tex]
[tex]$\frac{N^*}{N}=0.1738$[/tex]
Relative population in flame
T = 3000
[tex]$\frac{N^*}{N}=\frac{g^*}{g}e^{-\frac{\Delta E}{kT}}$[/tex]
[tex]$\frac{N^*}{N}=\frac{2}{1}e^{-\frac{-3.371\times 10^{-19}}{1.38 \times 10^{-23} \times 3000}}$[/tex]
[tex]$\frac{N^*}{N}=2 \times e^{-8.1425}$[/tex]
[tex]$\frac{N^*}{N}=2 \times 2.9090 \times 10^{-4}$[/tex]
[tex]$\frac{N^*}{N}=5.85 \times 10^{-4}$[/tex]
An old shade-tree mechanic trick for removing a stubborn bolt is to slip a long pipe over the handle of the wrench, then apply a force to the end of the pipe opposite the bolt.
Why is this effective? What problems might this technique cause?
Answer: long pipe is used to increase torque and reduce force needed.
Explanation: A torque is needed to open bolt. torque = F·r, if
R increases, Force F needed to open bold is smaller.
Problem is a worn bolt may break down. It sometimes I send useful to heat bolt instead using too much power.
what can i use to curl my eyelashes other den mascara and eyelash curler
Explanation:
a hot toothbrush. ......lol
assume the femur has a diameter of 3.0cm and a hollow center of 0.8cm diameter and a length of 50cm.if it is supporting a load of 600N/,what is the stress in the femur? How much will it be shortened by this load?Take the young's modulus for the femur bone as 16 × 10^9N/m²
Answer:
tbh i think hes right
Explanation:
The femur would be shortened by 0.0434 cm by a load of 600N.
What is pressure?The total applied force per unit of area is known as the pressure.
The pressure depends both on externally applied force as well the area on which it is applied.
The mathematical expression for the pressure
Pressure = Force /Area
As given in the problem assume the femur has a diameter of 3.0cm and a hollow center of 0.8cm diameter and a length of 50cm.if it is supporting a load of 600N,
The stress in the femur = force /area
=600 / π(.004²-.0015²)
= 13.89 ×10⁶ Pa
The length reduced by the load = PL/AE
= 13.89 ×10⁶ ×50/ 16 × 10⁹ cm
=0.0434 cm
The femur would be shortened by 0.0434 cm by a load of 600N.
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need help urgent please
To decrease the angle between the anterior surface of the foot and anterior surface of the lower leg is described as:
Answer:
dorsiflexion
Explanation:
To decrease the angle between the anterior surface of the foot and anterior surface of the lower leg is described as: dorsiflexion
Answer:
dorsiflexion
Explanation:
Hope this helps
A wave pulse travels along a stretched string at a speed of 100 cm/s. What will be the speed in cm/s if the string's tension is quadrupled, the length halved and its mass is doubled
Answer:
The new velocity of the string is 100 centimeters per second (1 meter per second).
Explanation:
The speed of a wave through a string ([tex]v[/tex]), in meters per second, is defined by the following formula:
[tex]v = \sqrt{\frac{T\cdot L}{m} }[/tex] (1)
Where:
[tex]T[/tex] - Tension, in newtons.
[tex]L[/tex] - Length of the string, in meters.
[tex]m[/tex] - Mass of the string, in kilograms.
The expression for initial and final speeds of the wave are:
Initial speed
[tex]v_{o} = \sqrt{\frac{T_{o}\cdot L_{o}}{m_{o}} }[/tex] (2)
Final speed
[tex]v = \sqrt{\frac{(4\cdot T_{o})\cdot (0.5\cdot L_{o})}{2\cdot m_{o}} }[/tex]
[tex]v = \sqrt{\frac{T_{o}\cdot L_{o}}{m_{o}} }[/tex] (3)
By (2), we conclude that:
[tex]v =v_{o}[/tex]
If we know that [tex]v_{o} = 1\,\frac{m}{s}[/tex], then the new speed of the wave in the string is [tex]v = 1\,\frac{m}{s}[/tex].
What is the resistance of a 15 ampere current with 8 volts of potential difference?
Answer:
Resistance in circuit = 0.53 ohm (Approx.)
Explanation:
Given:
Flow of current in circuit = 15 amp
Potential difference = 8 Volts
Find:
Resistance in circuit
Computation:
In an electrical system, resistance is a stopper of a material to electric current.
Resistance in circuit = Potential difference / Flow of current in circuit
Resistance in circuit = 8 / 15
Resistance in circuit = 0.53 ohm (Approx.)
A radial saw has a blade with a 9-in. radius. Suppose that the blade spins at 1000 rpm. (a) Find the angular speed of the blade in rad/min. Incorrect: Your answer is incorrect. webMathematica generated answer key rad/min (b) Find the linear speed of the sawteeth in ft/s. Incorrect: Your answer is incorrect. webMathematica generated answer key ft/
Answer:
The angular speed of the blade is of 166.67 rad/min
If a radial saw has a blade with a 9-in. radius. Suppose that the blade spins at 1000 rpm then the angular speed of the blade would be 104.72 rad/seconds.
What is speed?
The total distance covered by any object per unit of time is known as speed. It depends only on the magnitude of the moving object. The unit of speed is a meter/second. The generally considered unit for speed is a meter per second.
The mathematical expression for speed is given by
speed = total distance /Total time
As given in the problem If a radial saw has a blade with a 9-in. radius. Suppose that the blade spins at 1000 rpm then we have to find the angular speed of the blade,
the angular speed of the blade (ω) = 2πN/60
=2×π×1000/60
= 104.72 rad/seconds
Thus, the angular speed of the radial saw would be 104.72 rad/seconds
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Three identical very dense masses of 3800 kg each are placed on the x axis. One mass is at x1 = -
230 cm, one is at the origin, and one is at
x2 = 350 cm. Take the gravitational constant to be G = 6.67×10−11N⋅m2
/kg2
a) calculate the gravitational attraction of the object located at x1 on the object sitting at the
origin. (magnitude and direction. Take the direction from the origin to the right as
POSITIVE)
b) Calculate the gravitational attraction of the object located at X2 on the object at the origin.
(magnitude and direction)
c) Calculate the total gravitational attraction of the objects located at x1 and the object sitting at
x2 on the mass located at the origin. (magnitude and direction).
Answer:C
Explanation:
I think its c im pretty sure
why all monosacharides and dissacharides are soluble in waters
A 1.0-kg object moving 9.0 m/s collides with a 2.0-kg object moving 6.0 m/s in a direction that is perpendicular to the initial direction of motion of the 1.0-kg object. The two masses remain together after the collision, and this composite object then collides with and sticks to a 3.0-kg object. After these collisions, the final composite (6.0-kg) object remains at rest. What was the speed of the 3.0-kg object before the collisions
Answer:
v₃ = - (3 i ^ + 4 j ^) m / s
v₃ = 5 m / s, θ = 233º
Explanation:
This is a momentum problem. Let us form a system formed by the three objects so that the forces during the collisions have been internal and the moment is conserved.
Let's start working with the first two objects. As each object moves in a different direction let's work with the components in an xy coordinate system
X axis
initial instant. Before the shock
p₀ₓ = m₁ v₁₀ + 0
final instant. After the crash
p_{fx} = (m1 + m2) vₓ
the moment is preserved
p₀ₓ = p_{fx}
m₁ v₀₁ = (m₁ + m₂) vₓ
vₓ = [tex]\frac{m_1}{m_1+m_2} \ v_{o1}[/tex]
Y axis
initial instant
p_{oy} = 0 + m₂ v₀₂
final moment
p_{fy} = (m₁ + m₂) v_y
the moment is preserved
p_{oy} = p_{fy}
m₂ v₀₂ = (m₁ + m₂) v_y
v_y = [tex]\frac{m_2}{m_1 +m_2 } \ v_{o2}[/tex]
We already have the speed of the set of these two cars, now let's work on this set and vehicle 3
X axis
initial instant
p₀ₓ = (m₁ + m₂) vₓ + m₃ v₃ₓ
final instant
p_{fx} = 0
p₀ₓ = p_{fx}
(m₁ + m₂) vₓ + m₃ v₃ₓ = 0
v₃ₓ = [tex]- \frac{m_1+m_2 }{m_3} \ v_x[/tex]
Y Axis
initial instant
p_{oy} = (m₁ + m₂) v_y + m₃ v_{3y}
final moment
p_{fy} = 0
p_{oy} = p_{fy}
(m₁ + m₂) v_y + m₃ v_{3y} = 0
v_{3y} = [tex]- \frac{m_1+m_2}{m_3} \ v_y[/tex]
now we substitute the values of the speeds
v₃ₓ = [tex]- \frac{m_1+m_2}{m_3} \ \frac{m_1}{m_1+m_2} \ v_{o1}[/tex]
v₃ₓ = [tex]- \frac{m_1}{m_3} \ v_{o1}[/tex]
v_{3y} = [tex]- \frac{m_1+m_2}{m_3} \ \frac{m_2}{m_1+m_2} \ v_{o2}[/tex]
v_{3y} = [tex]- \frac{m_2}{m_3} \ v_{o2}[/tex]
let's calculate
v₃ₓ = - ⅓ 9
v₃ₓ = - 3 m / s
v_{3y} = - ⅔ 6
v_{3y} = - 4 m / s
therefore the speed of vehicle 3 is
v₃ = - (3 i ^ + 4 j ^) m / s
It can also be given in the form of modulus and angles using the Pythagorean theorem
v₃ = [tex]\sqrt{v_{3x}^2 + v_{3y}^2}[/tex]
v₃ = [tex]\sqrt{3^2+4^2}[/tex]
v₃ = 5 m / s
let's use trigonometry for the angle
tan θ' = [tex]\frac{v_{3y}}{v_{3x}}[/tex]
θ' = tan⁻¹ (\frac{v_{3y}}{v_{3x}})
θ' = tan⁻¹ (4/3)
θ' = 53º
That the two speeds are negative so this angle is in the third quadrant, measured from the positive side of the x axis
θ = 180 + θ'
θ = 180 +53
θ = 233º
In what way would a digital thermometer be preferable to those from a liquid-based thermometer?
mathematical expression between wave number and frequency
A particle with a charge of 34.0 $\mu C$ moves with a speed of 65.8 m/s in the positive $x$ direction. The magnetic field in this region of space has a component of 0.545 T in the positive $y$ direction, and a component of 0.828 T in the positive $z$ direction. What is the magnitude of the magnetic force on the particle
Answer:
0.00221 N
Explanation:
Given that,
The charge on the particle, [tex]q=34\mu C[/tex]
The speed of the particle, v = 65.8 m/s (+x direction)
Magnetic field, B = 0.545 T (in +y direction) and 0.828 T in the positive z direction.
The magnetic force is given by the formula as follows :
[tex]F=q(v\times B)[/tex]
Substitute all the values,
[tex]F=34\times 10^{-6}\times (65.8i\times (0.545j+0.828 k))\\\\=34\times 10^{-6}\times (65.8i\times 0.545j +65.8i\times 0.828 k)\\\\=34\times 10^{-6}\times(35.86k +(-54.48j))\\\\=34\times 10^{-6}\times \sqrt{35.86^2+54.48^2} \\\\=0.00221\ N[/tex]
So, the magnitude of the magnetic force on the particle is equal to 0.00221 N.
difference between centrifugal and semi-centrifugal clutches
Answer:
Semi-centrifugal clutches are used in high powered race cars, to reduce the driver effort. Working is just like semi-centrifugal clutch.
The clutch action is purely under centrifugal force.
At low engine rpm the centrifugal force is low, so there is slip, as engine rpm increases, so does the centrifugal force.
what is a magnetic flux thru closed surface
A string with a length of 0.75 m is fixed at both ends. (a) What is the longest possible wavelength for the traveling waves that can interfere to form a standing wave on this string? (b) If waves travel with a speed of 130 m/s on this string, what is the frequency associated with this longest wavelength?
Answer:
a) Longest wavelength is: [tex]\lambda_{1}=2*0.75=1.5\: m[/tex]
b) The frequency associated with this longest wavelength is: [tex]f=86.7\: Hz[/tex]
Explanation:
a)
The wavelength equation of a standing wave is given by:
[tex]\lambda_{n}=\frac{2}{n}L[/tex]
Where:
L is the length of the stringn is a natural numberWe use n=1 to find the longest possible wavelength, so we will have:
[tex]\lambda_{1}=2L[/tex]
[tex]\lambda_{1}=2*0.75=1.5\: m[/tex]
b)
The speed of the wave is given by:
[tex]v=f\lambda[/tex]
So we just need to find the f (frequency).
[tex]f=\frac{v}{\lambda}[/tex]
[tex]f=\frac{130}{1.5}[/tex]
[tex]f=86.7\: Hz[/tex]
I hope it helps you!
Which of the following is NOT true about Potential Energy?
An object's position affects its potential energy
O Objects with more mass have more potential energy
Potential energy is Stored energy
Potential energy only occurs when an object is in motion
Answer:
Potential energy only occurs when an object is in motion.
Explanation:
Energy can be defined as the ability (capacity) to do work. The two (2) main types of energy are;
a. Kinetic energy (K.E): it is an energy possessed by an object or body due to its motion.
Mathematically, kinetic energy is given by the formula;
[tex] K.E = \frac{1}{2}MV^{2}[/tex]
Where;
K.E represents kinetic energy measured in Joules.
M represents mass measured in kilograms.
V represents velocity measured in metres per seconds square.
b. Potential energy (P.E): it is an energy possessed by an object or body due to its position above the earth.
Mathematically, potential energy is given by the formula;
[tex] P.E = mgh[/tex]
Where,
P.E represents potential energy measured in Joules.
m represents the mass of an object.
g represents acceleration due to gravity measured in meters per seconds square.
h represents the height measured in meters.
Additionally, the mechanical energy of a physical object or body is the sum of the potential energy and kinetic energy possessed by the object or body.
Mathematically, it is given by the formula;
Mechanical energy = P.E + K.E
why is it important to know all about recreational activities?
Answer:
It's important
Explanation:
Mental wellness is critical to overall physical health. Participating in recreational activities helps manage stress. Taking time to nurture oneself provides a sense of balance and self-esteem, which can directly reduce anxiety and depression.
Answer:
Mental wellness is critical to overall physical health. Participating in recreational activities helps manage stress. Taking time to nurture oneself provides a sense of balance and self-esteem, which can directly reduce anxiety and depression.
Explanation:
Wind turbines continue to generate energy even when there isn't any wind.
O True
O False
True or false? Charges flow from high voltage to low voltage