Answer:
A) The distance between the stations is 1430m
B) The time it takes the train to go between the stations is 80s
Explanation:
First we will calculate the distance covered for the first 20s.
From one the equations of kinematics for linear motion
[tex]S = ut + \frac{1}{2}at^{2} \\[/tex]
Where [tex]S[/tex] is distance traveled
[tex]u[/tex] is the initial velocity
[tex]t[/tex] is time
and [tex]a[/tex] is acceleration
Since the train starts from rest, [tex]u[/tex] = 0 m/s
Hence, for the first 20s
[tex]a =[/tex] 1.1 m/s²; [tex]t =[/tex] 20s, [tex]u[/tex] = 0 m/s
∴ [tex]S = ut + \frac{1}{2}at^{2} \\[/tex] gives
[tex]S = (0)(20) + \frac{1}{2}(1.1)(20)^{2}[/tex]
[tex]S = \frac{1}{2}(1.1)(20)^{2}[/tex]
[tex]S =[/tex] 220m
This is the distance covered in the first 20s.
The train then proceeds at constant speed for 1100m.Now, we will calculate the speed attained here
From
[tex]v = u +at[/tex]
Where [tex]v[/tex] is the final velocity
Hence,
[tex]v = 0 + 1.1(20)[/tex]
[tex]v = 1.1(20)[/tex]
[tex]v =[/tex] 22 m/s
This is the constant speed attained when it proceeds for 1100m
The train then slows down at a rate of 2.2 m/s² until it stopsWe can calculate the distance covered while slowing down from
[tex]v^{2} = u^{2} + 2as[/tex]
The initial velocity, [tex]u[/tex] here will be the final velocity before it started slowing down
∴[tex]u[/tex] = 22 m/s
The final velocity will be 0, since it came to a stop.
∴ [tex]v[/tex] = 0 m/s
[tex]a = -[/tex]2.2 m/s² ( - indicates deceleration)
Hence,
[tex]v^{2} = u^{2} + 2as[/tex] gives
[tex]0^{2} =22^{2} +2(-2.2)s[/tex]
[tex]0=22^{2} - (4.4)s\\4.4s = 484\\s = \frac{484}{4.4} \\s = 110m[/tex]
This is the distance traveled while slowing down.
A) The distance between the stations is
220m + 1100m + 110m
= 1430m
Hence, the distance between the stations is 1430m
B) The time it takes the train to go between the stations
The time spent while accelerating at 1.1 m/s² is 20s
We will calculate the time spent when it proceeds at a constant speed of 22 m/s for 1100m,
From,
[tex]Speed =\frac{Distance}{Time}\\[/tex]
Then,
[tex]Time = \frac{Distance}{Speed}[/tex]
[tex]Time = \frac{1100}{22}[/tex]
Time = 50 s
And then, the time spent while decelerating (that is, while slowing down)
From,
[tex]v = u + at\\0 = 22 +(-2.2)t\\2.2t = 22\\t = \frac{22}{2.2} \\t= 10 s[/tex]
This is the time spent while slowing down until it stops at the station.
Hence, The time it takes the train to go between the stations is
20s + 50s + 10s = 80s
The time it takes the train to go between the stations is 80s
A ruler has a division of 1mm. You use the ruler to measure a piece of paper. You find that it is 7.4 cm wide and 8.3 cm long. What is the area of the piece of paper?
Answer:
6,142mm²Explanation:
Given the dimension of a paper measured by a ruler as 7.4 cm wide and 8.3 cm long, the area of the paper is expressed using the area for calculating the area of a rectangle as shown;
Area of the piece of paper = Length * Width
Given length = 7.4cm
Length = 74mm (Since 10mm = 1cm)
Width = 8.3cm
Width (in mm) = 83mm
We converted to mm since the ruler used to measure has a division of 1mm.
Substituting the given values into the formula, we will have:
Area of the piece of paper = 74mm * 83mm
Area of the piece of paper = 6,142mm²
Hence, the area of the piece of paper is 6,142mm²
Pls help
Qn 9,10,11
Qn 11
Answers,
a) 10g/cm3
b) 20g/cm3
c) 30g/cm3
d) 40g/cm3
Answer:
Q no. 9: a
Q no. 10: d
Q no. 11: b
potential energy is sometimes called?
Answer:
it can be called PE or sometimes, there are equations which you can use the letter U.
Explanation:
Answer:
STORED ENERGY
Explanation:
How long does it take a car to cross a 20m bridge if it starts from rest and accelerates at 5 m/s^2?
2s
1.89s
1.41s
1.41 m
2.8s
The correct answer is 2.8s
we do not use water instead of mercury in a barometer
Answer:
Mercury is commonly used in barometers because its high density means the height of the column can be a reasonable size to measure atmospheric pressure.
A football coach walks 18 meters westward, then 12 meters
eastward, then 28 meters westward, and finally 14 meters
eastward.
Answer:
Displacement = 20
Direction = westward
Explanation:
Given that a football coach walks 18 meters westward, then 12 meterseastward, then 28 meters westward, and finally 14 meters
eastward.
To calculate the displacement,
Let eastward = negative
Westward = positive
Displacement = 18 - 12 + 28 - 14
Displacement = 46 - 26
displacement = 20 metre
Since the answer is positive, the direction is westward.
Which title best fits Rahma's note
Rahma took these notes on a process involving the
movement of molecules, but she forgot to title them.
-Causes molecules to move until they are evenly
distributed
-Moves from high concentration to low
concentration
-Has no need for added energy
-Can occur with or without a membrane being
present
Active Transport in Cells
O Passive Transport in Cells
o Osmosis
O Diffusion
FIRST ANSWER GETS BRAINIEST
Answer:
diffusion is the answer.
Answer:diffusion
Explanation: it right
who is the winner of khatron khiladi made in india 2020
Answer:
karishma tanna
Explanation:
it is correct
Karishma Tanna was declared as the winner.
How did the atomic theory develop and change
Explanation:
Early Atomic theory
Although the idea of the atom was first suggested by Democritus in the fourth century BC, his suppositions were not useful in explaining chemical phenomena, because there was no experimental evidence to support them. It was not until the late 1700's that early chemists began to explain chemical behavior in terms of the atom. Joseph Priestly, Antoine Lavoisier, and others set the stage for the foundation of chemistry. They demonstrated that substances could combine to form new materials. It was the English chemist, John Dalton, who put the pieces of the puzzle together and developed an atomic theory in 1803.
Dalton's atomic theory contains five basic assumptions:
All matter consists of tiny particles called atoms. Dalton and others imagined the atoms that composed all matter as tiny, solid spheres in various stages of motion.
Atoms are indestructible and unchangeable. Atoms of an element cannot be created, destroyed, divided into smaller pieces, or transformed into atoms of another element. Dalton based this hypothesis on the law of conservation of mass as stated by Antoine Lavoisier and others around 1785.
Elements are characterized by the weight of their atoms. Dalton suggested that all atoms of the same element have identical weights. Therefore, every single atom of an element such as oxygen is identical to every other oxygen atom. However, atoms of different elements, such as oxygen and mercury, are different from each other.
In chemical reactions, atoms combine in small, whole-number ratios. Experiments that Dalton and others performed indicated that chemical reactions proceed according to atom to atom ratios which were precise and well-defined.
When elements react, their atoms may combine in more than one whole-number ratio. Dalton used this assumption to explain why the ratios of two elements in various compounds, such as oxygen and nitrogen in nitrogen oxides, differed by multiples of each other.
John Dalton's atomic theory was generally accepted because it explained the laws of conservation of mass, definite proportions, multiple proportions, and other observations. Although exceptions to Dalton's theory are now known, his theory has endured reasonably well, with modifications, throughout the years.
A freely suspended magnet does not point exactly at the geographical N-S direction
What is the following correct way to write 2,330,000 In a scientific notation
Answer:
2.33 × 10^6
hope this helps.
Answer:
2.33 x 106
Explanation:
it is right promise
Lee is traveling in a train moving at a constant velocity of 35 m/s to the east. If Lee is seated on the train and staring at the seat directly in front of him, how fast does the seat in front of Lee appear to be moving relative to Lee?
Answer:
0 m/s or stationary
The seat in front of Lee appear to be at rest
Explanation:
When the motion of a person or object is found by comparing the person or objects motion with regards to a stationary object or an object in motion, the result is the relative motion of the person or object to the stationary or moving object
In the question, Lee is comparing the motion of the chair in front of him with regards to the motion of the chair he his sitting on.
The speed of both chairs are the same as the speed of the train in which they are attached.
Therefore, as the seats are fixed relative to each other such that there is no change in their relative position and therefore, no or 0 m/s relative velocity with each other.
Which of the following element has seven total valence electrons? Your answer: argon helium oxygen bromine
Answer:
bromine
Explanation:
Any element in the halogen group will have seven valence electrons. These elements include fluorine, chlorine, bromine, iodine, and astatine
I am the distance between waves what am l
Answer:
My answer to the question is Wavelength
Answer:
Wavelength
Explanation:
Since this riddle is talking about “Distances”, wavelength is the distance between the crest of waves. This riddle and wavelength is similar... so I’m guessing the answer should be wavelength.
Therefore your answer would be Wavelength.
Hope this was helpful! :)
Brainliest would be highly appreciated! Thanks! :)
A boat that moves with a constant velocity of 12 m/s is moving on a river with a
constant current of 4 m/s. What is the resultant velocity of the boat if:
a) The boat is traveling to the north and the current is to the south?
b) The boat is traveling to the south and the current is to the south?
c) The boat travels to the east, across the current, while the current is to the south.
Explanation:
Given that,
Velocity of boat, [tex]v_b=12\ m/s[/tex]
Velocity of current, [tex]v_c=4\ m/s[/tex]
(a) If the boat is traveling to the north and the current is to the south,
[tex]v_b=12j\ m/s[/tex]
[tex]v_c=-4j\ m/s[/tex]
The resultant velocity,
[tex]v_r=12-(4)=8\ m/s[/tex] due North
(b) If boat is traveling to the south and the current is to the south,
[tex]v_b=-12j\ m/s[/tex]
[tex]v_c=-4j\ m/s[/tex]
Resultant velocity,
[tex]v_r=12+4=16\ m/s[/tex] due south
(c) If the boat travels to the east, across the current, while the current is to the south.
So,
[tex]v_r=\sqrt{12^2+4^2}\\ \\v_r=12.64\ m/s[/tex]
i will give brainliest Which of the following structures are present in plant cells but absent in animal cells? Choose 1 answer: (Choice A) A Cell walls (Choice B) B Mitochondria (Choice C) C Cytosol (Choice D) D Golgi bodies
Answer:
A. cell walls
Explanation:
Plants have cell walls but animals dont.
Explain why lenses are used for particular applications. ( please write a long detailed answer )
Answer:
Lenses are very important for us. Without lenses even we can't imagine the world. Without lenses our life is like life without colors.
Explanation:
Lenses are used everywhere around us in car, truck, glass, headlamps etc. It is also present in the flashlight of the LED light that is used in electronic materials.
Our eyes have also most amazing lenses. When you look at ground, at sky, and staring at moon all that happen that because of our binocular lenses. Our eyes have two type of lenses that concave lenses and convex lenses.
By these lenses we can see far and near object6s easily. Thus we used special applications of lenses to see the objects.
Dr. James hypothesizes that his patient, Jacob, misbehaves in class because it allows him to get attention from his
peers.
Which perspective BEST fits Dr. James beliefs about Jacob's actions?
Answer:
Hey there!
The answer would be a Behavioral perspective.
Let me know if this helps :)
john can travel to atlanta 560 miles in 9 hours what is his velocity
Answer:
132
Explanation:
An object with a density of 0.85 g/cc is dropped into each of the two beakers shown below. Beaker 1 has a density of 0.5 g/cc. Beaker 2 has a density of 1 g/cc. What will happen to the object in each case?
Answer:
The object will sink in the liquid in beaker 1.
The object will float in the liquid in beaker 2
Explanation:
The density of an object relative to the density of a fluid determines if the object floats or sink in a fluid. The density of a material is the measure of the amount of mass of that material packed into a unit volume of that material.
For the beaker 1, the liquid in this beaker has a density of 0.5 g/cc, which is lesser than the density of the object (0.85 g/cc). This means that the object will add more mass than there should be to the volume of the space it displaces within the field. This results in the object sinking in the fluid.
For beaker 2, the liquid in this beaker has a density of 1 g/cc, which is more than the density of the object (0.85 g/cc). This means that the object will add less mass than there should be to the volume of the space it displaces within the field. This results in the object floating in the fluid.
A small metal sphere has a mass of 0.19 gg and a charge of -23.0 nCnC. It is 10.0 cmcm directly above an identical sphere that has the same charge. This lower sphere is fixed and cannot move. If the upper sphere is released, it will begin to fall.What is the magnitude of its initial acceleration?
Answer:
a = -7.29 m / s²
Explanation:
For this exercise we must use Newton's second law,
F -W = m a
Force is electrical force
F = k q₁ q₂ / r²
k q₁ q₂ / r² -mg = m a
indicate that the charge of the two spheres is equal
q₁ = q₂ = q
a = (k q² / r² - m g) / m
a = k q² / m r² - g
Let's reduce the magnitudes to the SI system
m = 0.19 g (1kg / 1000 g) = 1.9 10⁻⁴ kg
q1 = q2 = q = -23.0 nC (1C / 10⁹ nC) = -23.0 10⁻⁹ C
r = 10.0 cm (1m / 100cm) = 0.1000 m
let's calculate
a = 9 10⁹ (23.0 10⁻⁹)² / (0.1000² 1.9 10⁻⁴) - 9.8
a = -7.29 m / s²
The negative sign indicates that the direction of this acceleration is downward
A scientist is trying to identify an unknown cell. He determines that it has a nucleus and lysosomes.
It also contains a cell membrane, but does not have a cell wall. What type of cell is the scientist most likely looking at?
Choose 1 answer:
(Choice A) A Animal cell
(Choice B) B Fungal cell
(Choice C) C Plant cell
(Choice D) D Bacteria
Answer:
Choice A) A Animal cell
Explanation:
Answer:
A.
Explanation:
A boat sailed 7 hours at speed of 80km/h
Answer:
No it’s 1,130
Explanation:
I did online
Acceleration is the change of velocity over some
time. Is it true or false
Experiment Question: How does temperature affect the air (gas) inside a balloon? Please help it's just the hypothesis I need help in. Also, this is NOT physics, it's SCIENCE!! (I couldn't find science, but yeah)
Answer:
I think when the balloon is heated up the gas will expand making the balloon bigger. When things are heated up the molecules will get excited and expand. When they balloon is cooled then the it will retract.
Hope this helps! :)
which of the following substances is a base? ammonia, distilled water, lemon juice, or vinegar
HELP PLZ "25 meters per second Northeast" is a description of
Speed
Acceleration
Velocity
Direction
Answer:
ion no
Explanation:
cuz i dont
Answer:
It is the SPEED of an object.
Explanation:
an electric heater takes 4 A when operated on 250 V supply. calculate the cost of the electricity consumed at 10k per kWh when the heater is used for 4 hours
Answer:
P=IV.
P=4×250=1000.
(1000/1000)kw×4.
1×4=4×10=40k.
A person holding a lunch bag is moving upward in a hot air balloon at a constant speed of 7.7 m/s . When the balloon is 21 m above the ground, she accidentally releases the bag. Part A What is the speed of the bag just before it reaches the ground
Answer:
The speed of the bag just before it reaches the ground is 21.71 m/s.
Explanation:
The speed of the bag can be found using the following equation:
[tex] v_{f}^{2} = v_{0}^{2} - 2gy [/tex]
Where:
[tex]v_{f}[/tex] is the final speed =?
[tex]v_{0}[/tex] is the initial speed = 7.7 m/s
g: is the gravity = 9.81 m/s²
y: is the height = 21 m
[tex]v_{f}^{2} = v_{0}^{2} - 2gy = (7.7 m/s)^{2} - 2*9.81 m/s^{2}*(-21 m) = 471.31 m^{2}/s^{2}[/tex]
[tex]v_{f} = 21.71 m/s[/tex]
Therefore, the speed of the bag just before it reaches the ground is 21.71 m/s.
I hope it helps you!
WILL GIVE BRAINLIEST AND A THANKS TO FIRST CORRECT ANSWER!!!!
Which statements describe processes involved in the accretion of planetesimals and protoplanets? Check all that apply.
Both involve the melting of solid materials in the nebula.
Both involve the formation of solid particles from nebular materials.
Both involve the work of the gravitational push on nebular materials.
Both involve the trapping of gases and the clumping of masses of matter.
Both involve the growing of gas grains with the addition of atoms and molecules.
Answer:2 and 4th one
Explanation: