Liquid Hydrogen is the fuel used by rockets.
Explanation:
- Liquid hydrogen which can be chemically denoted as "
" is often considered as the significant fuels for rocket.
- However rocket in its lower stages uses fuels such as Kerosene and oxygen where as in the higher stages such as second and third stages it uses liquid hydrogen.
- Liquid hydrogen is known to easily cool the nozzle and then also other parts of the rocket before mixing with the oxidizer such as the oxygen.
- Thus liquid hydrogen helps in preventing nozzle erosion and also reduces combustion chamber.
- Liquid hydrogen one the other hand is very expensive as 384,071 gallons of it will cost approximately $376,389.58
.
Thus liquid hydrogen is effectively used as a fuel for rocket.
Answer:
B. G = 333 mS, B = j250 mS
Explanation:
impedance of a circuit element is Z = (3 + j4) Ω
The general equation for impedance
Z = (R + jX) Ω
where
R = resistance in ohm
X = reactance
R = 3Ω X = 4Ω
Conductance = 1/R while Susceptance = 1/X
Conductance = 1/3 = 0.333S
= 333 mS
Susceptance = 1/4 = 0.25S
= 250mS
The right option is B. G = 333 mS, B = j250 mS
Answer:
It will be equivalent to 338.95 N-m
Explanation:
We have to convert 250 lb-ft to N-m
We know that 1 lb = 4.45 N
So foe converting from lb to N we have to multiply with 4.45
So 250 lb = 250×4.45 =125 N
And we know that 1 feet = 0.3048 meter
Now we have to convert 250 lb-ft to N-m
So 
So 250 lb-ft = 338.95 N-m
Solution :
The nuclear reaction for boron is given as :
And the reaction for Cadmium is :
![$^{113}\textrm{Cd}_48 + ^{1}\textrm{n}_0 \rightarrow ^{114}\textrm{Cd}_48 + \gamma [5 \ \textrm{MeV}]$](https://tex.z-dn.net/?f=%24%5E%7B113%7D%5Ctextrm%7BCd%7D_48%20%2B%20%5E%7B1%7D%5Ctextrm%7Bn%7D_0%20%5Crightarrow%20%5E%7B114%7D%5Ctextrm%7BCd%7D_48%20%2B%20%5Cgamma%20%5B5%20%5C%20%5Ctextrm%7BMeV%7D%5D%24)
We know that it is easier that to shield or stop an alpha particle (i.e. He nucli) as they can be stopped or obstructed by only a few centimetres of the material. However, the gamma rays ( γ ) can penetrate through the material to a greater distance. Therefore, we can choose the first one.
Answer:
Among the different types of excavation protection system, as a way of preventing accidents against cave-ins, the sloping involves cutting back the trench wall at an angle inclined away from the excavation. Shoring requires installing aluminum hydraulic or other types of supports to prevent soil movement and cave-ins. Shielding protects workers by using trench boxes or other types of supports to prevent soil cave-ins (OSHA). In addition, the regulations do not allow employees to work on excavations where there is an accumulation of water. If this occurs, water on the site must be constantly removed by suitable equipment preventing water from accumulating. The entry of surface water into the excavations must also be prevented by means of diversion ditches, dam, or other suitable means.
Explanation:
