Answer:
The pressure in the tunnel is 97.45 kPa
Explanation:
Given;
atmospheric pressure, P₁ = 101.3 kPa
air velocity in the tunnel, v₂ = 80 m/s
density of air at 20°C, ρ = 1.204 kg/m³
pressure in the tunnel, P₂ = ?
Apply Bernoulli's equation;
P₁ + ¹/₂ρv₁² + ρgz₁ = P₂ + ¹/₂ρv₂² + ρgz₂
v₁ = 0
z₁ = z₂ = 0
P₁ = P₂ + ¹/₂ρv₂²
P₂ = P₁ - ¹/₂ρv₂²
P₂ = 101.3 kPa - (0.5 x 1.204 x 80²)
P₂ = 101.3 kPa - 3.8528 kPa
P₂ = 97.45 kPa
Therefore, the pressure in the tunnel is 97.45 kPa
Suppose an octopus knows an enemy is nearby. Which two things would the octopus most likely do to escape?
A. Hide in a small space
B. Find something to eat
C. Attract a mate
D. Change its color
E. Show happiness or sadness
Answer:
A and D
Explanation:
The efficiency of a machine is 80%? What does it mean?
Answer:
It means how much input work you put into the machine, which then becomes output from the machine. So you're putting 80% of work into the machinie. To find the efficency of a machine, it's output divided by input work.
Explanation:
Answer:
efficiency is the ratio of the power ouput to the power input
Explanation:
It compares how much energy is used to do work versus how much is lost or wasted to the environment, the more efficient the machine, the less energy wasted.
Jamaal drove to the mountains to go camping. He drove 300 miles in 5 hours.
What was his average speed?
A. 45 mph
B. 55 mph
C. 50 mph
D. 60 mph
Answer:
D. 60
Explanation:
Divide 300 miles by 5
To escape from a horrible fire, two people are forced to jump from the third story of a burning building onto solid concrete. Which person is more likely to sustain fewer injuries: the jumper who comes to an abrupt halt when he lands or the jumper who bounces after impact?
The jumper who bounces after impact is more likely to sustain fewer injuries since he/she has a lesser change in momentum.
Impulse:According to the question:
Two people are forced to jump from the third story of a burning building onto solid concrete to escape the fire.
One person lands on the ground and comes to an abrupt halt.
The other person bounces off the ground after impact.
We know that the sudden change in momentum results in impulse. Impulse is directly proportional to the force exerted on the body. The greater the impulse, the larger the force exerted on the body.
If we assume that both the person have the same mass then:
The person coming to an abrupt halt has a larger change in momentum that the person who bounces off. Since the person who bounces off continues to be in motion, retaining some of the momenta while the direction of motion changes.
So the person who bounces after impact will sustain fewer injuries.
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When using the superposition theorem on a two-source network, if the current produced by one source is in one direction, while that produced by the other source is in the opposite direction through the same resistor Select one: A. a mistake in the sign of the result occurred. B. the resulting current is the difference of the two and has the direction of the larger current. C. all voltage sources were not properly converted to current sources. D. the absolute values of the two currents add algebraically, and the direction is the same as the direction of the larger current.
Answer: B. The resulting current is the difference of the two and has the direction of the larger current.
Explanation: Superposition Theorem states that the result in a particular branch of a linear circuit when a variety of sources are acting at the same time equals the sum of the response of each particular source acting at a time, i.e., if sources are acting on a line circuit, the resulting current in any branch is the sum of all the currents produced if each source is producing it by itself.
To solve by this method:
1) Find current in a particular branch considering one only independent source and deactivating the others;
2) Repeat the first step for all the sources in the circuit;
3) Add all the results: If the current obtained is in the same direction, add them; If it's in the opposite direction, subtract them and obtain the net current;
Therefore, when using superposition, if one current is in one direction and the other produced by other source is in the opposite direction, the net current is the difference between the two abd has the direction of the larger current.
please please please please
Answer:
....................
Answer:
20
Explanation:
40/2.0=20.......
hope it helps
Megan is eating a Snickers and decides not to finish the last it of it. She drops the snickers into a trashcan below. What happens to the speed of the piece of Snickers as it falls towards the trashcan?
Answer:
i like trains 45654
Explanation:
Which best describes a neutralization reaction?
a reaction between an acid and a base
a reaction between two acids
a reaction between a base and a salt
a reaction between two salts
Answer:
a reaction between an acid and a base
Explanation:
Answer:
The answer is A. A reaction between an acid and a base
Explanation:
Give reasons.
A stone thrown upward returns back to the earth surface.
Answer:
Gravity
Explanation:
Due to earths gravity, anything that goes into the air returns back to the surface unless it is given the ability to fly.
Hope this helps!
what was the main idea of Malthus theory of population
Answer:
The idea that population growth is potentially exponential while the growth of the food supply or other resources is linear.
Explanation:
Leah is sitting on of her surfboard out in the ocean. She is waiting for the perfect wave to come along so she can ride it in to
shore. As she waits, she notices that the waves roll by in patterns, or sets.
As Leah its, she counts the number of waves that pass her during a 10-second period; she counts just 1. She estimates that the
distance between crests is 6 meters. Betty sees the perfect wave and begins paddling. She pushes herself up, stands on the
surfboard and rides the wave all the way in to shore, a distance of about 60 meters. It takes her about 10 seconds to ride the
wave in. Use two methods to calculate the speed of the wave based on the information presented. Are they the same? Explain
how you got your answers.
Answer:
No
Explanation:
S=d/t Speed equals distance divided by time. That's a helpful equation in this case. Leah's wave took 10 seconds, and the distance was 6 meters.
6/10=.6
Betty's wave took 10 seconds, but the distance was 60 meters this time.
60/10=6
We know that 6 and .6 are not the same numbers, so we can see that the waves aren't the same.
<3
The effect wind has on an airplane can be modeled by using a wind tunnel. What is one limitation of this model
Answer:
The limitations of this this model is the amount of wind being blown to effect the airplane.
Answer: Highly skilled workers are necessary to run the wind tunnel.
Explanation: I took the quiz on A pex.
The image below shows the processes of mitosis and meiosis.
How do the products of mitosis compare to the products of meiosis?
A.
The cells from mitosis are identical to each other and to the parent cell, but the cells from meiosis are not identical to each other or the parent cell.
B.
The cells from mitosis are a requirement of sexual reproduction, but the cells from meiosis are a requirement of asexual reproduction.
C.
Mitosis produces sperm and egg cells, but meiosis produces body cells, like skin and muscle.
D.
Mitosis produces cells with half the chromosomes of the parent cell, but meiosis produces cells with the same chromosomes as the parent cell.
Answer:
It’s D
Explanation:
The cells from mitosis are identical to each other and to the parent cell, but the cells from meiosis are not identical to each other or the parent cell. Hence, option (A) is correct.
What are mitosis and meiosis?Chromosome replication and equitable distribution between the two daughter cells occur during the cell division process known as mitosis. Each daughter cell has the same number of chromosomes as the parent cell, making them diploid. Thus, mitosis is sometimes referred to as equational division.
Meiosis is a type of cell division that describes how germ cells divide, resulting in the fission of two nuclei. The two nuclear fissions, known as meiosis 1 and meiosis 2, result in the formation of four sex cells known as gametes. The number of chromosomes in each sex cell is divided in half from that of the parent cell. This type of cell division happens during reproduction when one cell divides into four haploid daughter cells. The nucleus divides into four daughter cells, or nuclei.
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A bar of gold has a temperature of 22 Celsius, and a bar of aluminum has a temperature of 27 Celsius. Which statement explains why the bar of aluminum as a higher temperature
Answer:Type of metal
Explanation:Basically certain types of metal may heat and get cold faster maybe the alumm may collect more sun and heat more and stay that way
Due to the higher thermal conductivity of aluminium, it has higher temperature than gold.
What is meant by thermal conductivity ?The ability of a material to conduct or transport heat is referred to as thermal conductivity.
Here,
It is not the solid itself that moves in bulk as a result of thermal conductivity; rather, it is molecular agitation and contact.
A region of high temperature and high molecular energy is moved towards a region of lower temperature and lower molecular energy via a temperature gradient.
The density of aluminium is small. It is easily castable, machinable, and formable, and it has a high thermal conductivity and great corrosion resistance.
At 20 °C, gold has an electrical resistivity of 0.022 micro-ohm m and a thermal conductivity of 310 W m-1 K-1.
Aluminium conducts more heat than gold.
Hence,
Due to the higher thermal conductivity of aluminium, it has higher temperature than gold.
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1. Define Inertia
2. Define Balenced force
3. Define Unbalenced force
Answer:
inertia:
a tendency to do nothing or to remain unchanged.
balanced force:
When two forces acting on an object are equal in size but act in opposite directions.
unbalanced force:
When two forces acting on an object are not equal in size.
Arctic sea ice has declined over the past few decades causing water levels to increase. This is an interaction of which two spheres? A)Biosphere and geosphere
B)Cryosphere and hydrosphere
C)Geosphere and atmosphere
D)Hydrosphere and geosphere
Answer:
B
Explanation:
Answer:
Its B)Cryosphere and hydrosphere! I took the test and got that question correct!
Explanation:
10 points
If a boat traveling East has a Net Force of 324 N, and the wind blowing
West has a Net Force of 789 N. What is the overall Net Force and which
side?
465 N, East
465 N, West
1113 N, West
1113 N, East
Answer:
465 N,East ............
Which statement correctly identifies the scientific question and describes why the question is scientific?
Answer:
i had this question as well!
Explanation:
Answer:
1. to the Mystic 2. A Theme or social value 3. Something that can be valued 4. Can’t be observed/ Noticed.
Explanation:
if the coefficient of friction between the block of mass 5 kg and ball is 0.5, then minimum force F required to hold the block with the wall is (g=10 m/s²)
Given parameters:
Mass of block = 5kg
Coefficient of friction = 0.5
g = 10m/s²
Unknown
Minimum force F required to hold the block =?
Solution:
Frictional force is a force that opposes motion.
The minimum force required to hold the block to the wall is the frictional force.
Frictional force = uN
Where u is coefficient of friction
N is the normal force
N = mg
where m is the mass of the body
g is the acceleration due to gravity
So,
Frictional force = umg
= 0.5 x 5 x 10
= 25N
The force required here is 25N
Why can concave mirror is used in cosmetic mirror
Answer:
"When face is placed between the concave mirror and its focus, it produces a magnified image. This enlarged image of face is helpful in makeup as even pores of skin are clearly visible."
The amount of thermal energy transferred between objects depends only on their masses and initial and final temperatures.
Question 17 options:
True
False
Answer:
False
Explanation:
The amount of energy transferred between objects not only depend on their masses, initial and final temperatures but also on their specific heat capacity.
The specific heat capacity plays an important role in ascertaining the amount of thermal energy a body can conduct.
Specific heat capacity is the amount of heat required to raise the temperature of 1kg of a substance by 1kelvin. This property is an intensive property of any matter and it determines to a large extent, how far matter are able to transfer energy.The equation;
H = m c Ф
where H is the amount of heat
m is the mass
c is the specific heat capacity
Ф is the change in temperature;
is used to find the amount of heat of a substance.
Answer:
false
Explanation:
Because the amount of energy is transferred between objects not only depend on their masses, initial and final temperatures but also on their specific heat capacity.
Hopes this helps you and it’s correct because I had this question on edgenuity
John and Suzie are trying to improve the speed of their race car by adjusting the angle of the rear spoiler. Which choice is the controlled variable(s)?
the maximum speed and the angle of the rear spoiler
the type of tire and the type of fuel
only the maximum speed
only the angle of the rear spoiler
Answer:
the type of tire and the type of fuel
Explanation:
PLEASE HELP ASAP
A golf ball is hit horizontally off the edge of a 30 m high cliff and lands
distance of 25 m from the edge of the cliff.
1. What is the initial vertical velocity of the golf ball?
2. At what time did the golf ball hit the ground?
3. What was the initial horizontal velocity of the golf ball?
4. What was the final horizontal velocity of the golf ball?
Answer:
1. Initial vertical velocity its 0m/s
2. 2.47 seconds
3. 10.12 m/s
4.10.12 m/s
Explanation:
Remember that we have here two parts of a problem, first we know that the ball made a free fall of 30 meters, since the ball was hit horizontally and doesn't state otherwise the vertical velocity is 0. To calculate the time we just use 30 m as our Height and use the formula for vertical distance on free fall:
[tex]H=\frac{g*t^{2} }{2} \\[/tex]
Now we just solve for time:
[tex]t=\sqrt{\frac{2H}{g} }[/tex]
With this we just insert the values we know:
[tex]t=\sqrt{\frac{2H}{g} }\\t=\sqrt{\frac{2*30}{9.81} }\\t=2.47[/tex]
Now we know that the ball was 2.47 seconds in the air, so the ball hti the ground at the second 2.47.
To calculate the velocity of the ball we just need to divide the horizontal distance covered by the time it spent on air:
[tex]v=\frac{d}{t} \\v=\frac{25}{2.47} \\v=10.12[/tex]
The final and initial horizontal velocity of the ball would be the same since nothing states otherwise, of course the hitting of the ground would decrease its velocity but since nothing is said in the problem it is not considered.
1. The initial-vertical velocity of the golf ball is equal to zero because the ball would start its motion from a stationary position (at rest).
2. The time it took the golf ball to hit the ground is 2.47 seconds.
3. The initial-horizontal velocity of the golf ball is 10.12 m/s.
4. The final-horizontal velocity of the golf ball is 10.12 m/s.
Given the following data:
Maximum height = 30 meters.Horizontal distance = 25 meters.1. The initial-vertical velocity of the golf ball is equal to zero because the ball would start its motion from a stationary position (at rest).
2. To determine the time it took the golf ball to hit the ground:
At maximum height, time is given by the formula:
[tex]Time = \sqrt{\frac{2H}{g} }[/tex]
Where:
g is the acceleration due to gravity.H is the maximum height.Substituting the given parameters into the formula, we have;
[tex]Time = \sqrt{\frac{2\times 30}{9.8} }\\\\Time = \sqrt{\frac{60}{9.8} }\\\\Time =\sqrt{6.12}[/tex]
Time = 2.47 seconds.
3. To determine the initial-horizontal velocity of the golf ball:
[tex]Horizontal\;velocity = \frac{Horizontal\;distance}{Time} \\\\Horizontal\;velocity = \frac{25}{2.47}[/tex]
Initial horizontal velocity = 10.12 m/s.
4. To determine the final-horizontal velocity of the golf ball:
The initial-horizontal velocity and final-horizontal velocity of the golf ball would be the same.
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10 points
5). A car accelerates from rest to the speed of 9.6m/s over a distance of
40.5m. Determine the acceleration of the car.
Explanation:
u=0 m/s
v=9.6 m/s
s= 40.5 m
a=?
V^2=u^2 +2as
9.6^2=0+2×a×40.5
92.16=81a
a=92.16/81
a=1.14m/s^2
You and your cycling partner are capable of producing 955 W of power. What's the fastest you can pedal up a 4.90 ∘ slope if the combined mass of your tandem bicycle and both riders is 139 kg and you face a 14.5-N force from air resistance?
Answer:
v= 7.3 m/s
Explanation:
Assuming that the cyclists are going uphill at constant speed, and neglecting friction between the tires and the road, the force exerted by the bikers must be equal and opposite to the force downhill.This force downhill, has two components, one due to gravity, and the other due to the air resistance.This last one is a given of the problem, 14.5 N.The force due to gravity along the slope of the road, can be showed that is as follows:[tex]F_{g} = m*g*sin\theta= 139 kg*9.8m/s2*sin 4.9 = 116.4 N[/tex]
So, the total force downhill is just the sum of the two:[tex]F_{net} =F_{g} + F_{air} = -130.9 N[/tex]
(Taking as positive the direction uphill)Now, we know that the maximum power to be developed by the bikers, is P=955 W = 955 J/sAs the power is energy per unit time, and the change in energy is equal to the work done, we can write the following expression:[tex]W = F* \Delta x = \Delta E = P*\Delta t[/tex]
As v = Δx/Δt, rearranging in the expression above, we get:P = F*vThe force must be equal in magnitude and opposite to the one acting downhill, that we have just got, so as P is a given, we need just to solve for v, as follows:[tex]v_{max} = \frac{P}{F_{up} } =\frac{955 W}{130.9N} = 7.3 m/s[/tex]
So the fastest the bikers can climb the slope is 7.3 m/s.ILL GIVE BRAINLIEST AND 5 POINT STAR RATING!!! Acid rain has a pH lower than 5.0 The lower the pH, the more acidic the rain. Which region of the United States receives the most acid rain? 1.Midwest 2.West 3.Northeast 4.South
Answer:
ome acid rain occurs naturally, but sulfur dioxide and nitrogen oxide emissions from smokestacks combine with rain to make sulfuric and nitric acid in amounts that harm the environment. The region of the United States most harmed by acid rain is the East Coast, including the Appalachian Mountains and the Northeast.
Explanation:
pls give me brainlist
If you push on an object that has a mass of 400 kg and it accelerates at 4 m/s2, what would the acceleration (a) be if the mass was reduced to 1/4 as much?
(Hint: Instead of plugging 400 kg into the equation, plug 100 kg into the equation as the mass but keep the force at 1,600 N.)
a
1/4 m/s2
b
16 m/s2
c
8 m/s2
d
4 m/s2
Answer:
b 16 m/s².
Explanation:
Hello.
In this case, the force exerted to the mass of 400 kg at an acceleration of 4 m/s² is:
[tex]F=400kg*4m/s^2=1600N[/tex]
Now, since the mass is decreased to 100 kg (1/4 of 400 kg), and the force remain the same, the new acceleration should be:
[tex]a=\frac{F}{m}=\frac{1600kg*m/s^2}{100kg}\\ \\a=16m/s^2[/tex]
Thus, the answer is b 16 m/s².
Best regards.
For a balloon to rise in the air, the lifting force
must be greater than which force: Gravity,
Normal, or Friction?
Help please
Mark brainlist
Answer:
gravity
Explanation:
Which of the following is man made and is used to store water for drinking or irrigation
Answer:
Reservoir.
Explanation:
HURRY PLS 30 MINS LEFT
A ball is rolling across the floor so that it is traveling along the positive x axis at 5.00 m/s. Due to the bend of the carpet fibers it experiences an acceleration of 1.25 m/s2 at an angle of -125.0o from the x axis.
A. What is the x component of the acceleration?
B. What is the y component of the acceleration?
C. What is the x component of the balls displacement after 3.00s?
D. What is the y component of the balls displacement after 3.00s?
E. What is the displacement of the ball over 3.00s?
Answer:
A) aₓ = -0.717 m / s² , B) a_{y} = -1.024 m / s², C) x = 11.77 m , D) y = -4.6 m ,
E) d = 12.64 m
Explanation:
For this exercise we will use trigonometry to decompose the acceleration, we are told that
a = 1.25 m /s² with an angle tea = 125º in a clockwise direction
A) cos θ = aₓ / a
aₓ = a cos θ
aₓ = 1.25 cos (-125)
aₓ = -0.717 m / s²
B) sin θ = [tex]a_{y}[/tex] / a
a_{y} = a sin θ
a_{y} = 1.25 sin (-125)
a_{y} = -1.024 m / s²
C) The displacement component
x = v₀ₓ t + ½ aₓ t²
let's calculate
x = 5 3 + ½ (-0.717) 3²
x = 11.77 m
D) the y component of the displacement
y = [tex]v_{oy}[/tex] t + ½ [tex]a_{y}[/tex] t²
in this case the initial velocity is zero
y = 0 + ½ (-1,024) 3²
y = -4.6 m
E) Let's use the Pythagorean theorem
d =√ (x² + y²)
d = √ (11.77² + 4.6²)
d = 12.64 m
