(20 points) A 1 mm diameter tube is connected to the bottom of a container filled with water to a height of 2 cm from the bottom. Air flows from the tube into the liquid and creates spherical bubbles with diameter about the diameter of the tube (1 mm). Everything is at 298 K. The tube is short but is connected to a much longer 2 m long hose that is 6 mm in diameter. The hose is connected to the gas supply. If there is no gas flow the water will leak into the tube and into the supply hose. When gas flows the water is blocked from entering the tube and bubbling starts. State all assumptions in answering the following questions. (a) What should be the minimum air flow rate and the gas supply pressure to keep the water from leaking back into the tube? (b) Is the flow in the hose laminar or turbulent? Is the flow in the tube laminar or turbulent?
Answers
Solution :
Given :
h = 2 cm
Diameter of the tube , d = 1 mm
Diameter of the hose, D = 6 mm
Between 1 and 2, by applying Bernoulli's principle, we get
As point 1 is just below the free surface of liquid, so
[tex]$P_1=P_{atm} \text{ and} \ V_1=0$[/tex]
[tex]$\frac{P_{atm}}{\rho g}+\frac{v_1^2}{2g} +h = \frac{P_2}{\rho g}$[/tex]
[tex]$\frac{101.325}{1000 \times 9.81}+0.02 =\frac{P_2}{\rho g}$[/tex]
[tex]$P_2 = 111.35 \ kPa$[/tex]
Therefore, 111.325 kPa is the gas supply pressure required to keep the water from leaking back into the tube.
Velocity at point 2,
[tex]$V_2=\sqrt{\left(\frac{111.135}{\rho g}+0.02}\right)\times 2g$[/tex]
= 1.617 m/s
Flow of water, [tex]$Q_2 = A_{tube} \times V_2$[/tex]
[tex]$=\frac{\pi}{4} \times (10^{-3})^2 \times 1.617 $[/tex]
[tex]$1.2695 \times 10^{-6} \ m^3/s$[/tex]
Minimum air flow rate,
[tex]$Q_2 = Q_3 = A_{hose} \times V_3$[/tex]
[tex]$V_3 = \frac{Q_2}{\frac{\pi}{4}D^2}$[/tex]
[tex]$V_3 = \frac{1.2695 \times10^{-6}}{\pi\times 0.25 \times 36 \times 10^{-6}}$[/tex]
= 0.0449 m/s
b). Reynolds number in hose,
[tex]$Re = \frac{\rho V_3 D}{\mu} = \frac{V_3 D}{\nu}$[/tex]
υ for water at 25 degree Celsius is [tex]$8.9 \times 10^{-7} \ m^2/s$[/tex]
υ for air at 25 degree Celsius is [tex]$1.562 \times 10^{-5} \ m^2/s$[/tex]
[tex]$Re_{hose}=\frac{0.0449 \times 6 \times 10^{-3}}{1.562 \times 10^{-5}}$[/tex]
= 17.25
Therefore the flow is laminar.
Reynolds number in the pipe
[tex]$Re = \frac{V_2 d}{\nu} = \frac{1.617 \times 10^{-3}}{8.9 \times 10^{-7}}$[/tex]
= 1816.85, which is less than 2000.
So the flow is laminar inside the tube.
Related Questions
Proper ventilation is required when welding, so that you don't ____________.
A) Breathe in dangerous fumes
B) Cause an area to smell like smoke
C) Overheat
D) Burn yourself
(This is for my Automotive class)
Answers
A bronze bushing 60 mm in outer diameter and 40 mm in inner diameter is to be pressed into a hollow steel cylinder of 120-mm outer diameter. Calculate the tangential stresses for steel and bronze at the boundary between the two parts
Answers
Answer:
The tangential stress for the steel at 30mm = 88.8MPa.
The tangential stress for the steel at 60mm = 35.5 MPa.
The tangential stress for the bronze at 20mm = - 191.9 MPa.
The tangential stress for the bronze at 30mm = - 138.6 MPa.
Explanation:
The outer radius bronze bushing = 60 mm/2 = 30 mm, the inner radius for bronze bushing = 40mm/2 = 20mm and the cylinder radius = 120mm/2 = 60mm.
Step one: The first step is to calculate or Determine the interface pressure.
The interface pressure = 0.05/ [ [ 30 × ( 1/210 ×10⁹) ] × [( 60² + 30²/ ( 60² - 30²) + 0.3 ] + [ 1/105 × 10⁹× [ ( 20² + 30²)/( 30² - 20²) - 0.3] ].
The interface pressure = 53.3 MPa
Step two: Determine the tangential stresses for steel and bronze as given below:
The tangential stress for the steel at 30mm = 10⁶ × 53.3 [ ( 0.06)² + (0.03)²/ ( 0.06)² - (0.03)² ] = 88.8 MPa.
The tangential stress for the steel at 60mm = 10⁶ × 53.3 × 2 × [0.03]²/ ( 0.06)² - (0.03)² ] = 35.5 MPa.
The tangential stresses for the bronze is calculated below;
=> The tangential stress for the bronze at 20mm = - [ 10⁶ × 53.3 × 2 × [0.03]² ] / ( 0.03)² - (0.02)² ] = - 191.9 MPa.
The tangential stress for the bronze at 30mm = - [ 10⁶ × 53.3 × [ 0.03]² + (0.03)² ] / ( 0.03)² - (0.02)² ] = - 138.6 MPa.
Which term refers to an application of biotechnology to forensic science?
Cloning
Transgenesis
Bioprocessing
DNA profiling
Biomanufacturing
Answers
Answer:
DNA profiling
Explanation:
took the test
In addition to bandages and gauze, it's recommended that a first aid kit also contain ___________.
A) Portable eyewash bottles
B) Tweezers
C) A finger splint
D) Scissors
Answers
In addition to bandages and gauze, it's recommended that a first aid kit also contain scissors. The correct option is D.
What is First aid?First aid is the initial and urgent care given to anyone who has either a small or significant disease or injury, with the goal of preserving life, preventing the condition from getting worse, or assisting in the healing process.
First aid is the initial and urgent care given to anyone who has either a small or significant disease or injury, with the goal of preserving life, preventing the condition from getting worse, or assisting in the healing process.
A first aid kit normally contains :
1. plasters
2. scissors
3. bandages
4. antiseptic ointments or lotions
5. basic medicines
6. gauzes
Anyone who has been hurt in an accident or has been injured can receive quick and basic medical care with the help of these materials.
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A(94,0,14) B(52,56,94) C(10,6,48) D(128,64,10)
The goal of the assignment is to apply methods of transforming orthogonal projections to solving metric problems.
The coordinates of four points ABCD are given (see next table). Determine the following values by transforming projection planes:
• 1. The size of the dihedral angle at the edge AB.
• 2. The shortest distance between ribs DA and BC.
• 3. Distance from vertex D to plane ABC.
• 4. Natural size of triangle ABC.
An example how to complete the task is shown after the table
Answers
9514 1404 393
Answer:
see below
Explanation:
We presume the drawing you want is contained in the figure you attached. The true sizes are identified with corresponding numbers.
Without your example, or your given methods of transforming projections, it is difficult to tell exactly how you want to compute the various distances or sizes.
the term applied to the chemistry of the body
Answers
Answer:
Biochemistry
Explanation:
Hope this helps :)
Answer:
Biochemistry
Have an amazing day!
A piston–cylinder device contains 15 kg of saturated refrigerant-134a vapor at 280kPa. A resistance heater inside the cylinder with a value of 110V is used to transfer heat of 20.67kJ/kg to the refrigerant at constant pressure for 6min. Determine the current supplied if the final temperature is 75℃
Answers
Answer:
18.77 A
Explanation:
To solve this we use the energy balance equation, that is:
[tex]E_{in}-E_{out}=\Delta E_{sys}\\\\Q_{in}+W_{in}+W_{out}=\Delta U\\\\Q_{in}+W_{in}=\Delta U\\\\But\ W_{in}=Voltage(V)*Current(I)*change\ in\ time(\Delta t)=VI\Delta t,\Delta U=m(h_2-h_1)\\\\Given\ that\ m=15kg,V=110\ V,\Delta t=6\ min = (6*60\ s)=360\ s,Q_{in}=20.67\ kJ/kg*15\ kg=310.05\ kJ=310050\ J\\\\From\ table: At\ P_1=280kPa, h_1=249.71\ kJ/kg=249710\ J/kg;At\ P_2=280kPa \ and\ T_1=75^oC,P_2=319.95\ kJ/kg=319950\ J/kg\\\\Substituting:\\\\310500+(110*360*I)=15(319950-249710)\\\\[/tex]
[tex]39600I=1053600-310500\\\\39600I=743100\\\\I=18.77\ A[/tex]
Which is a better hydraulic cross section for an open channel: one with a small or a large hydraulic radius?
Answers
Rod of steel, 200 mm length reduces its diameter (50 mm) by turning by 2 mm with feed speed 25 mm/min. You are required to calculate the metal removal rate (MRR)
Answers
Answer:
Explanation:
The material rate of removal is the total amount of material removed per unit time during any operation. The material rate of removal is usually given by the formula
Material Rate of Removal = Radial Depth of Cut * Axial Depth of Cut * Feed Rate, where
Radial Depth of Cut, RDOC = 25 mm
Axial depth of cut, ADOC = 200 mm
Feed rate, FR = 25 mm/min
On multiplying all together, we will then have our Material Rate of Removal, which is
MRR = 25 mm * 200 mm * 25 mm/min
MRR = 125000 mm³/min
Or we convert it to cm³/min and have
MRR = 125000 mm³/min ÷ 1000
MRR = 125 cm³/min
15 kg of ice at 0°C is heated to water of temperature 20°C. What is the amount of heat required if the specific latent heat of ice fusion is 335 kJ/kg and the specific heat capacity of water is 4.19kJ/kg/°C?
Answers
Answer:
6282 kJ
Explanation:
Given that:
The mass (m) = 15 kg
The specific latent heat of ice fusion [tex]h_{fg}_{ice}[/tex] = 335 kJ/kg
The specific heat capacity of water = 4.19 kJ/kg.c
The initial temperature of the ice [tex]T_i[/tex]= 0° C
The final temperature of the water [tex]T_f[/tex] = 20° C
To find the needed amount of heat to convert 0° C ice to 20° C of water.
To do that, we need to find the latent heat required for the phase change from 0° C ice to 0° C water, then the heat required to convert 0° C water to 20° C water.
Heat required = [tex]m \times h_{fg}_{ice}+ m \times c_{water} \times \Delta T[/tex]
Heat required = (15 × 335) + (15 × 4.19) × (20 - 0)
Heat required = 5025 + 62.85 × 20
Heat required = 5025 + 1257
Heat required = 6282 kJ
Water vapor at a rate of 40,000 kg/h and at 8 MPa and 500 C enters an adiabatic turbine and leaves the turbine at 40 kPa as saturated vapor. The rate of entropy generation for this turbine is close to,
Answers
Answer:
M(dot)= 40000 kg/h Pressure= 8Mpa and T= 500C If its adiabatic then you know that it loses no heat or Q(dot) =0 You have a turbine which drives a shaft producing work for the other systems.We want to find entropy production of alpha.What is the base unit that is divided in an engineering scale?
An engineering scale is based on unit increments of a/n ____.
Answers
Explanation:
The most often used architect's scale is 1/4" = 1'-0". The basic unit of measure for metric scales is the millimeter (mm). Drafting scales are either open-divided or full-divided.
I really have no clue if this is right or not because, well, I'm not an expert.
If this is wrong, don't hesitate to report my answer if it's wrong.
The vector from the origin to point A is given as (6, −2, −4), and the unit vector directed from the origin toward point B is (2, −2, 1)/3. If points A and B are ten units apart, find the coordinates of point B.
Answers
Following the given vectors, the coordinates of point B are given as (7.38, -7.38, 3.92). This was arrived at by utilizing the constraint of the distance between points A and B.
What is a Constraint?In mathematics, a constraint refers to a condition or requirement that the problem indicated must satisfy. That is, it is a permanent factor in the equation of that problem.
What is the solution to the problem above?Taking the vector quantities:
(6, -2, -4)
We can state that the Vector taken from the origin of Point B will be expressed as a multiple of the unit vector - U⁸= (2/3, -2/3, 1/3).
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Given these observed times (in minutes) for five elements of a job, determine the observed time (OT) for each element. Note: Some of the elements occur only periodically. (Round your answers to 2 decimal places.) CYCLE Element 1 2 3 4 5 6 1 1.2 1.2 1.2 1.2 1.2 - 2 - .7 - .7 - 0.7 3 2.2 2.2 2.2 3.2 2.2 2.2 4 3.2 - - 4.2 - - 5 0.7 .7 1.2 0.7 0.7 0.7
Answers
Answer:
Following are the solution to this question:
Explanation:
[tex]CYCLE[/tex]
[tex]Element \ \ \ \ \ \ 1\ \ \ \ \ \ 2 \ \ \ \ \ \ 3 \ \ \ \ \ \ 4 \ \ \ \ \ \ 5 \ \ \ \ \ \ 6 \ \ \ \ \ \ Average[/tex]
[tex]1 \ \ \ \ \ \ 1.2 \ \ \ \ \ \ 1.2 \ \ \ \ \ \ 1.2 \ \ \ \ \ \ 1.2 1.2 \ \ \ \ \ \ - \ \ \ \ \ \ 1.2\\\\[/tex]
[tex]2 \ \ \ \ \ \ - \ \ \ \ \ \ .7 \ \ \ \ \ \ - \ \ \ \ \ \ .7 \ \ \ \ \ \ - \ \ \ \ \ \ 0.7 \ \ \ \ \ \ 0.7 \\\\3 \ \ \ \ \ \ 2.2 \ \ \ \ \ \ 2.2 \ \ \ \ \ \ 2.2 \ \ \ \ \ \ 3.2 \ \ \ \ \ \ 2.2 \ \ \ \ \ \ 2.2 \ \ \ \ \ \ 2.36\\\\[/tex]
[tex]4 \ \ \ \ \ \ 3.2 \ \ \ \ \ \ - \ \ \ \ \ \ - \ \ \ \ \ \ 4.2 \ \ \ \ \ \ - \ \ \ \ \ \ - \ \ \ \ \ \ 3.7\\\\5 \ \ \ \ \ \ 0.7 \ \ \ \ \ \ .7 \ \ \ \ \ \ 1.2 \ \ \ \ \ \ 0.7 \ \ \ \ \ \ 0.7\ \ \ \ \ \ 0.7\ \ \ \ \ \ 0.78[/tex]
[tex]Element \ \ \ \ \ \ \ \ \ \ \ \ Observed \ time \\\\1 \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 1.2\\\\2 \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 0.7\\\\3 \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 2.36\\\\4 \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 3.7\\\\5 \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 0.78[/tex]
list the major parts in a shop's air supply system
Answers
Answer:
Compressed air systems usually consist of the following components:
compressor.
air cooler.
air receiver tank.
filter.
dryer.
condensate trap.
distribution system
Answer:
Compressed air systems usually consist of the following components:
compressor.
air cooler.
air receiver tank.
filter.
dryer.
condensate trap.
distribution system
Explanation:
Compressed air systems usually consist of the following components:
compressor.
air cooler.
air receiver tank.
filter.
dryer.
condensate trap.
distribution system
Whose responsibility is it to identify confined spaces and reduce hazards? A The employee B The rescuer C The employer D OSHA
Answers
Answer:
C. The Employer
Explanation:
Under OSHA's Confined Space Standard, it is the responsibility of the "employer" to identify or evaluate the spaces whether they are "permit spaces" or "confined spaces." These spaces have serious safety hazards or health hazards. Examples: tanks, vessels, pits, underground vaults, and the like.
The employers need to disclose the information of the permit spaces and their risks to the employees. Thus, he should have a written permit of the permit space if he will be allowing the employees to enter. It is also the employer's responsibility to reduce the hazards imposed to the employees such as verifying the entry conditions that are acceptable, making sure the permit space is isolated, providing barriers, etc.
Naomi needs to test an application that will be accessed by multiple users simultaneously. She is planning to use LoadRunner to test the performance of the application. How can a testing tool such as LoadRunner help her with performance testing?
A.
by using a large number of testers
B.
by increasing the number of test cases
C.
by automating your test cases
D.
by creating a number of virtual users
Answers
Steam enters a steady-flow adiabatic nozzle with a low inlet velocity (assume ~0 m/s) as a saturated vapor at 6 MPa and expands to 1.2 MPa.
a. Under what conditions is the velocity from this nozzle maximized?
b. Determine the maximum exit velocity of the steam, in m/s.
Answers
This happens as a result of a gain in kinetic energy at the expense of a decrease in enthalpy brought on by gas expansion as air passes through the diverging region of the nozzle.
What velocity from this adiabatic nozzle maximized?A nozzle is a tool used to change the characteristics of a fluid flow as it leaves a confined chamber or conduit, particularly to enhance velocity. The reciprocal of the nozzle length, pressure, and the square root of the nozzle diameter all increase air velocity.
A nozzle needs to be made to expand steam from 500 PA at 210 °C to 100 kPa at a rate of 0.1 kg/s. In order to reach critical or sonic conditions (i.e., choked flow) at its throat, the flow is accelerated when a nozzle is used.
Therefore, The steam's specific volume at the nozzle's exit is determined to be 1.4 m3/kg and its velocity at that point to be 700 m/s.
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A lake is fed by a polluted stream and a sewage outfall. The stream and sewage wastes have a decay rate coefficient (k) of 0.5/day (1st order units). Assuming complete mixing and no other water losses or gains, what is the steady-state pollutant concentration as mg/L in the lake? Incoming Stream: C = 10 mg/L, Q = 40 m^3/s Sewage Outfall: C = 100 ppm, Q = 0.5 m^3/s Lake: V= 200 m^3
Answers
Solution :
Given :
k = 0.5 per day
[tex]$C_s = 10 \ mg/L \ ; \ \ Q_s= 40 \ m^3/s$[/tex]
[tex]$C_{sw} = 100 \ ppm \ ; \ \ Q_{sw}= 0.5 \ m^3/s$[/tex]
Volume, V [tex]$= 200 \ m^3$[/tex]
Now, input rate = output rate + KCV ------------- (1)
Input rate [tex]$= Q_s C_s + Q_{sw}C_{sw}$[/tex]
[tex]$=(40 \times 10) + (0.5\times 100)$[/tex]
[tex]$= 2 \times 10^5 \ mg/s$[/tex]
The output rate [tex]$= Q_m C_{m}$[/tex]
= ( 40 + 0.5 ) x C x 1000
[tex]$=40.5 \times 10^3 \ C \ mg/s$[/tex]
Decay rate = KCV
∴[tex]$KCV =\frac{0.5/d \times C \ \times 200 \times 1000}{24 \times 3600}$[/tex]
= 1.16 C mg/s
Substituting all values in (1)
[tex]$2 \times 10^5 = 40.5 \times 10^3 \ C+ 1.16 C$[/tex]
C = 4.93 mg/L
Type the correct answer in the box. Spell all words correctly.
Who focuses on planning a long-term business?
focus on planning a long-term business.
Reset
Next
Answers
Explanation:
A business man who really focus on victory achieved through a right procedure will focus on long-term planning.
Let us understand what a short-term and long-term planning is.
Short-term will plan only for two-three years. But a long-term plan will look for future five years income projection, plan of expansion, bigger goals, etc.
A business man is the person who take risks and achieve more. A victory can be achieved in many ways one is taking bigger risks, next is focusing on long-term plans
If this is wrong, give me the answer choices so I know what's right or wrong. I'll edit the question if given to me.
_____ refers to the knowledge and skills necessary to manage, control, and work with hazardous materials and pollutants.
Answers
A heat exchanger is used to recover waste heat from an industrial furnace and use it to heat pressurized water. The heat exchanger consists of a tube bank with a square 10 x 10 array of thin-walled smooth tubes (total of 100 tubes). The tubes are aligned in-line with a transverse pitch, ST = 50 mm. Each tube is 25 mm in diameter and 4 m long. Water passes through each tube at a flow rate of 0.025 kg s-1, so the total flow rate through all 100 tubes is 2.5 kg s-1. The exhaust gas is in cross-flow over the tubes, with an upstream velocity of 5.0 m s-1 and total flow rate of 2.25 kg s-1. The exhaust gas has properties similar to air. The inlet temperatures of the water and exhaust gas are 300 K and 800 K, respectively. (a) What is the overall heat transfer coefficient between the water and the gas? (b) What are fluid outlet temperatures? As a first approximation, assume the water flow through the tubes is fully developed and turbulent, with an estimated bulk mean temperature of 350 K. Use a mean temperature of 600 K and properties of air to represent the exhaust gases. Please comment on the accuracy of these assumptions after you obtain your results, but you do not need to repeat any calculations.
Answers
Answer:
Explanation:
ok this is as test dont cheat i d
Type the correct answer in the box. Spell all words correctly.
A genetically engineered hormone, , can treat Mary’s child for growth hormone deficiencies by stimulating body growth and increasing muscle mass.
Answers
Answer:
recombinant human growth
Explanation:
Answer:
recombinant human growth
Explanation:
yes
Rod of steel, 200 mm length reduces its diameter (50 mm) by turning by 2 mm with feed speed 25 mm/min. You are required to calculate the metal removal rate (MRR)
Answers
Answer:
125 cm³/min
Explanation:
The material rate of removal is usually given by the formula
Material Rate of Removal = Radial Depth of Cut * Axial Depth of Cut * Feed Rate, where
Radial Depth of Cut = 25 mm
Axial depth of cut = 200 mm
Feed rate = 25 mm/min
On multiplying all together, we will then have
MRR = 25 mm * 200 mm * 25 mm/min
MRR = 125000 mm³/min
Or we convert it to cm³/min and have
MRR = 125000 mm³/min ÷ 1000
MRR = 125 cm³/min
A light commercial building located in Philadelphia, Pa has construction and use characteristics much like a residence and design heating load of 120,000 Btu/h and cooling of 60,000 Btu/h. Determine the following: (a) Heating energy requirement, Btu(b) Gallons of No. 2 fuel oil/year, assuming efficiency of the furnace is 75 %(c) Cubic feet of natural gas/year(d) kWh of electricity for cooling for air conditioner with SEER of 8.5 using degree day method.(6 points)
Answers
Answer:
b
Explanation:
For a soil, cohesion is 15 kN/sq.M, unit weight is 20 kN/cu.M and the factor of safety is 1.5 along with stability number of 0.05. The safe maximum height of slope is *
Answers
Answer:
10 m
Explanation:
The Soil Cohesion is the force that holds together molecules or like particles within a soil.
The unit weight of a soil mass is the ratio of the total weight of soil to the total volume of soil.
The stability number (Sn) is given by the formula:
[tex]S_n=\frac{C_m}{\gamma *H}[/tex]
Given that:
Cohesion = C = 15 kN/m², Factor of safety = FOS = 1.5, unit weight = γ = 20 kN/m³, H = maximum height, Sn = 0.05. Hence:
[tex]C_m=\frac{C}{FOS}\\\\S_n=\frac{C}{\gamma *FOS *H}\\\\H= \frac{C}{\gamma *FOS *S_n}\\\\Substituting:\\\\H=\frac{15}{20*1.5*0.05} \\\\H=10\ m[/tex]
Which one of the following skills is a software engineer specializing in system support expected to possess?
ability to correct system maintenance issues
ability to direct traffic between devices
ability to develop user programming
ability to recommend system upgrades
Answers
Answer:
A. Ability to correct system maintenance issues
Explanation:
As a systems engineer, you will be responsible for a range of tasks, including management of IT systems, working with software developers to design and document new system architecture, and testing and implementing processes to improve the efficacy of existing systems.
Select three mechanical processes used in the manufacturing phase of engineering.
Drying
Mixing
Cooling
Crystallization
Size reduction
Food packaging
Answers
Answer:Size reduction
Cooling
Mixing
Explanation:
What is the step in which you are testing your hypothesis
Answers
Answer:
Step 1: State your null and alternate hypothesis. ...
Step 2: Collect data. ...
Step 3: Perform a statistical test. ...
Step 4: Decide whether the null hypothesis is supported or refuted. ...
Step 5: Present your findings.
What’s are the preventive strategies for workplace violence