Answer:
Plumbing using a one-way check valve to stop water flowing back on a pump when the pump shuts off.
Explanation:
Diodes are like check valves, keeping current from flowing both ways. Used to create d.c. out of a.c by rectification. Also to block flow if d.c. power like a battery is hooked up in reverse polarity.
Answer:
While resistance welding you should wear clear grinding glasses, unbreakable plastic face shields or clear unbreakable plastic goggles. When resistance welding a #10, or more, shade lens should be worn. All hand and portable tools should be inspected for loose parts, cleanliness, or worn power cords.
Answer:
The voltage needed to accelerate the electron beam is 2.46 x 10^16 Volts
Explanation:
The rate of electron flow is given as:
q = 1015 electrons per second
The total current is given by:
Total Current = (Rate of electron flow)(Charge on one electron)
Total Current = I = (1015 electrons/s)(1.6 x 10^-19 C/electron)
I = 1.624 x 10^-16 A
Now, we know that electric power is given as:
Electric Power = Current x Voltage
P = IV
V = P/I
V = 4 W/1.624 X 10^-16 A
<u>V = 2.46 x 10^16 Volts</u>
Without PPE, employees are at risk of Cuts and punctures. Chemical burns. Electric shocks. Exposure to excessive noise or vibration.
Answer:
W=-109.12 kJ/kg
Q=-76.34 kJ/kg
Explanation:
The needed work W we will calculate by using the work equation for polytropic process and the heat transfer Q we will calculate by using the energy balance equation.
Before the calculations we first need to determine the final temperature T2. We will do that by using the given initial temperature T1 = 10°C, the given initial p_1 = 120 kPa and final p_2 = 800 kPa pressure and the polytropic index n = 1.2. Before the calculation we need to express the temperature in K units.
T1 = 10°C + 273 K = 283 K
T2 = ((p_2/p_1)^(n-1)/n)* T1
T2 = 388 K
Now we can use the heat capacity C_v, = 0.3122 kJ /kg K and the temperatures T1 and T2 to determine the change in internal energy ΔU.
ΔU = C_v*(T2-T1)
ΔU = 32.78 kJ/kg
to determine the work we will also need the initial v1 and final v2 specific volume. The initial specific volume v1 we can determine from the ideal gas equation. For the calculation we will need the initial pressure p_1, temperature T1 and the specific gas constant R = 0.2081 kJ /kg K.
v1=R*T1/p_1
v1=0.4908 m^3/kg
For the final specific volume we need to replace the initial temperature and pressure with the final.
v2=R*T2/p_2
v2=0.1009 m^3/kg
The work W is then:
W=p_2*v2-p_1*v1/n-1
W=-109.12 kJ/kg
The heat transfer Q we can calculate form the energy balance equation. For the calculation we will need the calculated work W and the change in internal energy ΔU.
Q=W+ΔU
Q=-76.34 kJ/kg
