A fireboat is to fight fires at coastal areas by drawing seawater with a density of 1030 kg/m3 through a 10-cm-diameter pipe at a rate of 0.04 m3/s and discharging it through a hose nozzle with an exit diameter of 5 cm. The total irreversible head loss of the system is 3 m, and the position of the nozzle is 3 m above sea level. For a pump efficiency of 70 percent, determine the required shaft power input to the pump and the water discharge velocity.
Answer:
50.93 m/s
199.5 kW
Explanation:
From the question, the nozzle exit diameter = 5 cm, Radius= diameter/2= 5cm/2= 2.5cm. we can convert it to metre for unit consistency= (2.5×0.01)=
0.025m
We can calculate the The cross sectional area of the nozzle as
A= πr^2
A= π ×0.025^2
= 1.9635 ×10^- ³ m²
From the question, the water is moving through the pipe at a rate of 0.1 m /s , then for the water to move through it at a seconds, it must move at
(0.1 / 1.9635 ×10^- ³ m²)
= 50.93 m/s
During the Operation of the pump, the Dynamic energy of the water= potential energy provided there is no loss during the Operation
mgh = 1/2mv²
We can make "h" subject of the formula, which is the height of required head of water
h = (1/2mv²)/mg
h= v² / 2g
h = 50.93² / (2 ×9.81)
h = 132.21m
From the question;
The total irreversible head loss of the system = 3 m,
the given position of nozzle = 3 m
the total head the pump needed=(The total irreversible head loss of the system + the position of the nozzle + required head of water )
=(3 + 3 + 132.21m)
=138.21m
mass of water pumped in a seconds can be calculated since we know that mass is a product of volume and density
Volume= 0.1m³
Density of sea water=1030 kg/m
(0.1 m^3× 1030)
= 103kg
We can calculate the Potential enegry, which is = mgh
= (103 ×9.81 × 138.21)
= 139651.5 Watts
= 139.65kW
To determine required shaft power input to the pump and the water discharge velocity
Energy= efficiency × power
But we are given efficiency of 70 percent, then
139651.5 Watts = 0.7P
=199502.18 Watts
P=199.5 kW
Therefore, the required shaft power input to the pump and the water discharge velocity is 199.5 kW
HELP ASAP TIMER
Three trains are all are moving along a track with the same speed and slam on their brakes. If all three trains have identical coefficients of kinetic friction with the rail surface, which train travels the longest distance to come to a stop?
a
This cannot be determined, without knowing the normal force on the train by the rail.
b
The most massive train.
c
They all travel the same distance in stopping.
d
The least massive train.
Answer:
the more massive train i think
Explanation:
more mass means kinda more energy so it will take it longer to slow since it is larger
Plz di all plz i will give brainest and thanks to best answer do it right
Answer:
B
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hdhdgdtdtdt
gsgdgdggd
Explanation:
I TIHNK IS THE ANSWER
Answer:
C
Explanation:
Wave length is - - - - >
Bsjejwakknsbsbehebebbdbdbs
Who might be suffering from dissociative fugue?
Answer:
More common in adults.
Explanation:
a 50.0kg skydiver experience a 740newton air resistance force determine her acceleration please help asap
Answer:
a = - 5 [m/s²].
Explanation:
To solve this problem we must use Newton's second law, which tells us that the sum of forces on a body is equal to the product of mass by acceleration.
∑F = m*a
where:
F = resultant force [N] (units of Newtons)
m = mass = 50 [kg]
a = acceleration = 9.81 [m/s²]
For this particular problem, the only forces acting are the force of gravity acting down with negative sign, while the force of air opposes the fall, in this way it is positive.
[tex]f_{air}-F_{grav}=-m*a[/tex]
As the movement is pointing down the acceleration will be taken as negative.
[tex]740-(50*9.81)=-50*a\\740-490.5 = -50*a\\249.5 = -50*a\\a = - 5 [m/s^{2} ][/tex]
We should note that in this case, the acceleration has a negative sign, this means that the force of the air makes the skydiver move upwards
A 10 N force and an 18 N force act in the same direction on an object. What is the net force on the object?
Answer:
28 N
Explanation:
From the question given above, we were told that 10 N force and 18 N force act in the same direction on the object.
The net force acting on the object can be obtained by simply adding both forces together since they both act on the object in the same direction. This is illustrated below:
Force 1 (F₁) = 10 N
Force 2 (F₂) = 18 N
Net force (Fₙ) =?
Fₙ = F₁ + F₂ (since they both act in the same direction)
Fₙ = 10 + 18
Fₙ = 28 N
Therefore, the net force acting on the object is 28 N.
why are incandescent lights fo inefficient?
Answer:
Explanation:
Incandescent bulbs are extremely inefficient because 90% of the energy is wasted as heat, with only 10% being converted to visible light. This gives incandescent bulbs a luminous efficiency rating of around 2%. Ultimately, incandescent bulbs perform better as heaters than as light sources.
12. How many grams of beryllium are needed to produce 36.0 g of hydrogen? (Assume an excess of water.)
Be(s) + 2H, O() → Be(OH)2 (aq) +H,(g)
a
4.00 g
b. 36.0 g
c. 162 g
d 324 g
Answer:
Answer is: 162 g of beryllium.
Chemical reaction: Be + 2H₂O → Be(OH)₂ + H₂.
m(H₂) = 36,0 g.
m(Be) = ?
n(H₂) = m(H₂) ÷ M(H₂)
n(H₂) = 36,0 g ÷ 2 g/mol = 18 mol.
from reaction: n(Be) : n(H₂) = 1 : 1.
n(Be) = n(H₂) = 18 mol.
m(Be) = n(Be) · M(Be).
n(Be) = 18 mol · 9 g/mol = 162 g.
Answer:
Answer is: 162 g of beryllium.
Chemical reaction: Be + 2H₂O → Be(OH)₂ + H₂.
m(H₂) = 36,0 g.
m(Be) = ?
n(H₂) = m(H₂) ÷ M(H₂)
n(H₂) = 36,0 g ÷ 2 g/mol = 18 mol.
from reaction: n(Be) : n(H₂) = 1 : 1.
n(Be) = n(H₂) = 18 mol.
m(Be) = n(Be) · M(Be).
n(Be) = 18 mol · 9 g/mol = 162 g.
Which of the following is an example of light energy being changed to chemical energy?
A flashlight with rechargeable batteries
A solar panel that charges a battery
Food that is eaten to provide mechanical energy
A switch that flips up to turn on a light
Answer:
solar panels that charges battery
Particles in which state of matter are the most likely to interact with each other to cause a chemical reaction?
help guysssssssssssssssssssssssssssss
Answer: D) Earthquake
I hope this helps, and Happy Holidays! :)
Answer: Earthquakes
Explanation: Earthquakes impact rupture breaks in the ground, landslides, avalanches, fires, tsunamis, property damage, and loss of life.
Why doesn’t the force you exert when sitting on a chair cause the chair to move?
a. The floor exerts a balancing force on the chair.
b. The floor exerts too much force on the chair
c. The floor exerts an unbalancing force on the chair.
d. The floor exerts no force on the chair.
Answer:
the answer is A
Explanation:
Sonya pushes his friend down the road on his new wagon. Which two terms accurately describe the net force acting on the sled?
Group of answer choices
balanced and contact
unbalanced and noncontact
balanced and noncontact force
unbalanced and contact
Answer:
unbalanced and contact
Explanation:
The two terms that bests describes the net force acting on the sled is an unbalanced and contact force.
Force is a pull or push on a body. We have two main types of forces. Contact forces acts on a body and they must be in touch with it. An example is frictional force.
Non - contact forces acts based on force field and they are not in contact with the body. An example is gravitational force.
Since the sled is sliding down the road, it is changing velocity and so, unbalanced forces are acting on it.Therefore, the force on the wagon is an unbalanced and contact force.
a car travels 200km in 3.0 hours. Determine the average velocity of the car
Answer:
66.67 km/hrExplanation:
The average velocity of the car can be found by using the formula
[tex]a = \frac{d}{t } \\ [/tex]
d is the distance
t is the time taken
From the question we have
[tex]a = \frac{200}{3} \\ = 66.66666...[/tex]
We have the final answer as
66.67 km/hrHope this helps you
41. What effects the efficiency of a pulley?
a. the type of rope or cable
b. the way the wheel turns
c. the length of the rope
d. how big the wheel is
e. only a and be
f. all of the above
Answer:
e. only a and b
A 20 kg mass is hanging on one side of a pulley and a 5 kg mass is hanging on the other. Determine the acceleration of each mass.
Answer:
i believe it's 7
Explanation:
hand pushes on table with force of 35 N forward. whats the reaction force
Answer:
i think it is newtons third law of motion but i'm not sure sorry.i just really need point i don't know the answer.
Explanation:
Please select the word from the list that best fits the definition
Wave that has vibration in a direction that is perpendicular to the motion creating it
transverse wave
longitudinal wave
mechanical wave
Answer:
Transverse wave
Explanation:
What two things does force depend on
Answer:
When dealing with the force of gravity between two objects, there are only two things that are important – mass, and distance or (acceleration)
Explanation:
D. Ampere
A screw of length 5 cm enters totally into a wooden block after 25 turns. What is the pitch of the
screw?
A. 0.1 cm
B. 0.2 cm
C. 0.4 cm
D. 0.5 cm
Answer:
0.5
Explanation:
u must simplyfiy
When a person strikes and lights a match, potential energy in the match is transformed into which types of energy?
electrical and thermal
thermal and radiant
radiant and nuclear
nuclear and kinetic
hurry brainliest ill give 49 points
Answer:
Radiant and thermal
Explanation:
Electrical and thermal don't make sense because you are not using electricity to light the match. Radiant and nuclear is not right because you are not using nuclear energy to light the match. Nuclear and kinetic isn't right because you are using kinetic and you are not using nuclear energy.
Answer:
answer is B. thermal and radiant
Explanation:
just got it right on edge
A supply plane drops a package to the ground for stranded campers below. After falling for 8.14 seconds, the package will have a downward velocity of 80.79 m/s. How high was the plane when it dropped the package?
Answer:
333 m
Explanation:
The following data were obtained from the question:
Initial velocity (u) = 0 m/s.
Time (t) = 8.14 s.
Final velocity (v) = 80.79 m/s.
Acceleration due to gravity (g) = 9.8 m/s²
Height (h) =?
v² = u² + 2gh
80.79² = 0 + (2 × 9.8 × h)
6527.0241 = 0 + 19.6h
6527.0241 = 19.6h
Divide both side by 19.6
h = 6527.0241 / 19.6
h = 333 m
Thus, the plane was at a height of 333 m when the package was dropped.
Identify the type of motion that occurs when a body moves around its own center of mass.
circular
revolution
rotation
resolution
Answer:
circular
Explanation:
1. Four identical elephants are at different heights. If your physics teacher
asked you which of the following elephants has the greatest amount of
potential energy, what will be your answer? And why?
Helpppp:(((((
Which of the following best describes refraction?
Answer:
The medium sound waves
Explanation:
change in the direction of a wave passing from one medium to another.
These the flow of electrons (the current) and where some of the electrons' energy gets converted into heat. (Lessons 5.01-5.03) electric currents Insulators Resistors Conductors
Answer: The answer is resistors
Explanation: I just took the unit test and it was correct
In interactions of action-reaction pairs involving Earth and everyday objects, the effect on Earth's motion is often negligible because
Answer:
...The earth has a great mass. Since mass and inertia are directly proportional to each other, the larger the mass of the object, the more inertia that it has. Inertia is the objects resistance to a change in motion.
Explanation:
What do we know about the relative strength of the electric field around each object?
Answer:
A charged object in an electric field experiences a force due to the field. The electric field strength, E, at a point in the field is defined as the force per unit charge on a positive test charge placed at that point.
Explanation:
Any one their to help
A popular ride at an amusment park lifts
customers up to a height of 50 m and then
drops them threw a displacement of 50 m
before slowing them to a stop. How fast
are the customers going at the 50 m
mark?
Answer:
five dollars
Explanation:
im thick lol
A phase diagram assumes______
is kept constant.
Odensity
O volume
O temperature
O pressure