Two trains traveling towards one another on a straight track are 300m apart when the engineers on both trains become aware of the impending Collision and hit their brakes. The eastbound train, initially moving at 97.0 km/h Slows down at 3.50ms^2. The westbound train, initially moving at 127 km/h slows down at 4.20 m/s^2. What is the distance between them once they stop (express your answer to the two significant figures)
Answer:
48 m
Explanation:
Two trains traveling towards one another on a straight track are 300m apart when the engineers on both trains become aware of the impending Collision and hit their brakes. The eastbound train, initially moving at 97.0 km/h Slows down at 3.50ms^2. The westbound train, initially moving at 127 km/h slows down at 4.20 m/s^2.
The eastbound train
First convert km/h to m/s
(97 × 1000)/3600
97000/3600
26.944444 m/s
As the train is decelerating, final velocity V = 0 and acceleration a will be negative. Using third equation of motion
V^2 = U^2 - 2as
O = 26.944^2 - 2 × 3.5 S
726 = 7S
S = 726/7
S1 = 103.7 m
The westbound train
Convert km/h to m/s
(127×1000)/3600
127000/3600
35.2778 m/s
Using third equation of motion
V^2 = U^2 - 2as
0 = 35.2778^2 - 2 × 4.2 × S
1244.52 = 8.4S
S = 1244.52/8.4
S2 = 148.2 m
S1 + S2 = 103.7 + 148.2 = 251.86
The distance between them once they stop will be
300 - 251.86 = 48.14 m
Therefore, the distance between them once they stop is 48 metres approximately.
Which of the following is a characteristic of both scientific laws and theories? A. based on scientific evidence B. explain natural phenomena C. based on the opinions of scientists D. not subject to change
Answer:
A base on scientific event
Explanation:
theories can changeD
they dont explain unusual phenomenaB
Nothing is personal in scienceC
What is 4.2 converted into grams
Explanation:
4.2 converted to grams equal 119.067997125
In a walking investigation, Josephine
walked a total distance of 40 feet. At the
halfway point, she had walked for 25
seconds. She stopped for 5 seconds to tie
her shoe and then continued for 25 more
seconds. Sketch a graph that shows
Josephine's distance from the starting point
over time
Explanation:
She walked 20 feet in the first 25 seconds. Then she stayed at the 20 foot position for 5 seconds. Then she walked another 20 feet in 25 seconds. See attached graph.
A carpenter apprentice was killed when he was struck in the head by a nail that was fired from a powder actuated tool. The tool operator, while attempting to anchor a plywood form in preparation for pouring a concrete wall, fired the gun, causing the nail to pass through the hollow wall. The nail traveled some twenty-seven feet before striking the victim. The tool operator had never received training in the proper use of the tool, and none of the employees in the area were wearing personal protective equipment. What should be recommended to prevent this accident from happening again?
Answer:
Explanation:
The recommendations that need to be urgently addressed by the workshop and it's employees are
1) Training of all employees (particularly the tool operators) on the safe and proper use of all tools used in the course of the carpentry work.
2) Training of all employees in health, safety and environment (HSE). This training will help them appreciate the importance of always wearing personal protective equipment (PPE) when at the workshop or during the course of a work (because if the apprentice was putting on an engineer's helmet, he could have been safe).
3) Employees who fail to adhere strictly to the use of PPE should be sanctioned or even dismissed from the workplace
Which of the following is true of the structures labeled A in the cell membrane?
Choose 1 answer:
(Choice A) A They are membrane proteins.
(Choice B) B They are entirely hydrophobic.
(Choice C) C They are phospholipids.
(Choice D) D They are carbohydrates. Report a problem
Answer:
they are membrane proteins
Within the nebula that was the start of our solar system, a shock wave from an exploding supernova triggered dust particles to be drawn together to form a dense spherical cloud. The accumulation of dust set off a chain reaction. As the core of the cloud attracted more dust, its gravitational pull increased. As this pull increased so did all BUT its
Answer:
B expansion
Explanation:
In a cloud of gas and dust known as the solar nebula, the Sun and the planets jointly created 4.6 billion years ago. The solar nebula presumably collapsed as a result of a shock wave from a nearby supernova explosion. Thus, option A is correct.
What nebula that was the start of our solar system?A nearby supernova explosion's shock wave is most likely what caused the solar nebula to collapse.The planets formed in a thin disk around the Sun, which formed in the centre of the solar system. Moons began to form similarly around the gas giant planets.
Every speck of stuff in the solar system was once a massive nebula, or floating interstellar cloud, before it was shaped into a tidy collection of planets.
Therefore, a shock wave from an exploding supernova triggered dust particles to be drawn together to form a dense spherical cloud.
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What is the strength of electric field EpEp 0.60 mmmm from a proton? Express your answer to two significant figures and include the appropriate units.
Answer:
3.99*10^-3N/C
Explanation:
Using
Ep= kq/r²
Where r = 0.6mm = 0.6*10^-3m
K= 8.9*10^9 and q= 1.6*10^-19
So = 8.9*10^9 * 1.6*10^-19/0.6*10^-3)²
= 3.99*10^-3N/C
3. Which statement best describes the research projects that are funded by private
foundations?
a. Research projects that have little chance of success
b. Research projects for a specific cause
c. Research projects concerning the environment
d. Research projects that benefit consumers
Answer:
b. Research projects for a specific cause
Explanation:
Research funded by private foundations are usually for a specific cause. These type of research are usually properly scrutinized, and must have a high probability of success. Most of these projects may not be to benefit the consumers, but are usually done with a special purpose in mind.
A dog runs 300m North and sees the dog catcher and runs 120 m south .Whats the dogs displacement.The same jogger runs 3 miles around the track, starting and finishing in the same time after completing exactly 12 laps. What is the average velocity now
Answer:
1. 180 m
2. 1.5 miles/hour
3. 0 m/s
Explanation:
The complete question is
A dog runs 300 m North and sees the dog catcher and runs 120 m south Whats the dogs displacement.
A jogger runs north for 3.0 miles. If this took 2.0 hours, what is the jogger’s average velocity in miles per hour?
The same jogger runs 3.0 miles on the track, starting and finishing his run after completing exactly 12 laps around the track. What is his average velocity?
1. Displacement is how far the dog moves from the original starting point.
If the dog runs 300 m north, and then 120 m south, then the displacement from the starting point will be
displacement = 300 - 120 = 180 m
2. Displacement of the jogger = 3 miles
Time taken by the jogger = 2 hours
velocity of the jogger = ?
Velocity is = displacement/time
velocity = 3/2 = 1.5 miles/hour
3. velocity = displacement/time
if the jogger completes exactly 12 laps around the track, then the jogger will return to the starting point. This means that the jogger's displacement from the starting point is 0 miles
Jogger's velocity will therefore be = 0 m/s
How does online gaming affect the health of the student
Answer:
because we more see th online gaming and not eat food and playing that game all the time so it effect the health
hope you like it please follow me
Click at the above pic and the ans will appear.
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A scientist views an unknown cell under a microscope. Which of the following observations would support the claim that it is a plant cell rather than an animal cell? Choose 1 answer: (Choice A) A It has a cell membrane. (Choice B) B It has chloroplasts. (Choice C) C It is round in shape. (Choice D) D It has a nucleus.
Answer:
Choice A. It has chloroplast
Plants have chloroplast and animals dont
Explanation:
It having chloroplasts is the observation which would support the claim that it is a plant cell rather than an animal cell.
What is a Chloroplast?This is as organelle which produces the pigment known as chlorophyll and it is used during the process of photosynthesis.
Plants are known as primary producers and are involved in this process which is why option B was chosen.
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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: the answers are
(2)Both involve the formation of solid particles from nebular materials
And
(4)Both involve the trapping of gases and the clumping of masses of matter
Explanation:
What is the acceleration of softball if it has a mass of 5 kg and hits the catchers glove with a force of 35 N
Answer:
50m/s2^
Explanation:
We know , by newton's law of motion .
F=ma
a=f/m
a=25/0.5
a=50m/s2^
Therefore , the acceleration of a softball is .
Answer:
7 m/s²
Explanation: Force = Mass x acceleration
Also note that 1 N = 1 kg.m/s²
a=F/ m
a= 35 N/ 5 kg = 35 kg.m/ s² ÷ kg Aside:( so you cross out the kg)
a= 7 m/s²
Two point charges are separated by a certain distance. How does the strength of the electric field produced by the first charge, at the position of the second charge, change if the second charge is doubled?
Answer:
The field will remain the same
Explanation:
This is because electric field given as
E1= kq1/r²
And that of second charge
E² = kq2/r²
Is not affected by the size of the second charge q2
Determine the mass of the object below to the correct degree of precision.
272.83 g
272.9 g
272.90 g
272.94 g
Answer : The correct degree of precision is 272.94 g.
Explanation :
Precision : It is defined as the closeness of two or more measurements to each other.
For Example: If you weigh a given substance five times and you get 2.7 kg each time. Then the measurement is said to be precise.
Level of precision is determined by the maximum number of decimal places.
In the given figure, the value of mass of object is 280 g. From the given options we conclude that the 272.94 g is more close to 280 g and has maximum number of decimal places. So, 272.94 g measurement is said to be precise.
Therefore, the correct degree of precision is 272.94 g.
the unit for the measure of distance is
Answer: Well their are many Miles, inches, kilometres, meters, cementers, and so on.
hope it helps you bye
Centimetre, Meter, & Kilometre
New theories usually don’t start “from scratch.” For example, the modern model of the atom is the result of new information added to the cloud model. What is the main difference between the cloud model of the atom and the modern model? Group of answer choices Only the modern model includes protons. The cloud model does not include neutrons. Electrons move in specific orbits in the modern model. Electrons exist in a cloud around the nucleus in the cloud model.
Answer:
Electrons move in specific orbits in the modern model.
Explanation:
I'm still learning so, and D is not the answer.
The main difference between the cloud model of the atom and the modern model is that electrons exist in a cloud around the nucleus in the cloud model.
New theories usually don’t start “from scratch.” For example, the modern model of the atom is the result of new information added to the cloud model.
What is the main difference between the cloud model of the atom and the modern model?
Only the modern model includes protons. NO. Protons were discovered by Rutherford and are part of both models.The cloud model does not include neutrons. NO. Neutrons, discovered by Chadwick, are part of both models.Electrons move in specific orbits in the modern model. NO. Electrons in the modern model move in diffuse areas known as orbitals.Electrons exist in a cloud around the nucleus in the cloud model. YES.The main difference between the cloud model of the atom and the modern model is that electrons exist in a cloud around the nucleus in the cloud model.
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A ball is thrown upward from an initial height of 1.5m the ball reaches a height of 5m then falls to the ground . What Is the distance traveled by the ball? What is the displacement of the ball?
Answer:
8.5m and 3.5mExplanation:
In this problem, we are expected to solve/find the total distance traveled and also the displacement of the ball.
given that the initial height is 1.5m and was thrown to a height of 5m
the total distance covered when the ball falls to the ground
Note (see attached a rough sketch for the pictorial explanation)
1. The distance for A to B= 3.5 m
2. The distance from B to A= 3.5 m
3. The distance fro A to C= 1.5 m
the total distance is 3.5+3.5+1.5= 8.5m
the displacement is simply the difference between the final position and the initial position
displacent= 5-1.5= 3.5m
please anyone help me to answer this questions.plzz... it's very urgent..
Answer:
1) 3 applications of pressure in daily life are :-
● The area of sharp edge of knife, scissor or handsaws are much less then blunt edge. So, for same total force pressure is more for sharp edges than the blunt one. Hence sharp knife, scissors etc, cuts easily than a blunt one.
●Broad handles in bags and suitcases are provided for the comfort. Broad handles have large area. So, the pressure exerted on hands and shoulders would be small while carrying the bags and the suitcases.
●Trucks carrying heavy loads have more than four tyres. More tyres in case of trucks increase the area of contact with the road. This results in reduced pressure on the tyres.
2) Area of the surface which is on ground = 1.5×1
= 1.5m^2
Mass of the block = 300kg
Force applied by the block = Mass × g = 300×10
= 3000N (where g = acceleration due to gravity )
Pressure = Force applied / Area of the surface
= 3000N / 1.5m^2
= 2000 Pa
3)
a) The above experiment signifies that more the area of the surface of an object , less the pressure an object applies.
b) B exerts the minimum pressure because the area of its surface to ground is greater than others & as it has more area of surface , it exerts less pressure. ( area is inversely proportional to pressure )
c) D exerts the maximum pressure because the area of its surface to ground is lesser than others & as it has less area of surface , it exerts more pressure. ( area is inversely proportional to pressure )
d) It depend upon the way an object is kept on ground. If an object is kept in such a way dat the area of the surface to the ground is more , then pressure will be least exerted .If an object is kept in such a way dat the area of the surface to the ground is less, then pressure will be exerted more .
e) Do it yourself . only i will suggest that make the tip of the cone ( which is to the ground ) more narrower.
Explanation:
A scientific LAW has been proven and a THEORY has not. True Or False
Answer:
true
Explanation:
i did the test its right
Answer:
true
mark mine as brainiest, i could use the points
Select the correct equations that show that a freely falling rock drops a distance of 80 m when it falls from rest for 4 s .
Answer:
1 and 4
Explanation:
A hollow plastic sphere is held below the surface of a fresh-water lake by a cord anchored to the bottom of the lake. The sphere has a volume of 0.650 cubic meters and the tension in the cord is 900 N. a) Calculate the buoyant force exerted by the water on the sphere. b) what is the mass of the sphere? c) the cord breaks and the sphere rises to the surface. When the sphere comes to rest, what fraction of its volume will be submerged?
Answer: a) B = 6811N
b) m = 603.2kg
c) 86.8%
Explanation: Buoyant force is a force a fluid exerts on a submerged object.
It can be calculated as:
[tex]B=\rho_{fluid}.V_{obj}.g[/tex]
where:
[tex]\rho_{fluid}[/tex] is density of the fluid the object is in;
[tex]V_{obj}[/tex] is volume of the object;
g is acceleration due to gravity, is constant and equals 9.8m/s²
a) For the hollow plastic sphere, density of water is 1000kg/m³:
[tex]B=10^{3}.0.695.9.8[/tex]
B = 6811N
b) Anchored to the bottom, the forces acting on the sphere are Buoyant, Tension and Force due to gravity:
B = T + [tex]F_{g}[/tex]
B = T + mg
mg = B - T
[tex]m=\frac{B - T}{g}[/tex]
Calculating:
[tex]m=\frac{6811 - 900}{9.8}[/tex]
m = 603.2kg
c) When the shpere comes to rest on the surface of the water, there are only buoyant and gravity acting on it:
B = m.g
[tex]\rho_{w}.V_{sub}.g=m.g[/tex]
[tex]V_{sub}=\frac{m}{\rho_{w}}[/tex]
[tex]V_{sub}=\frac{603.2}{1000}[/tex]
[tex]V_{sub}[/tex] = 0.6032m³
Fraction of the submerged volume is:
[tex]\frac{V_{sub}}{V_{obj}}[/tex] = [tex]\frac{0.6932}{0.695}[/tex] = 0.868
Calculate the de Broglie wavelength of a 4.5-MeV α particle. Explain if a relativistic or non-relativistic approach is required
Answer:
4.4x10^-32m
Explanation:
Using
Wavelength = hc/E
= 6.63*10^-34 * 3x10^8/ 4.5 x10^ 6ev
= 4.4*10^-32m
Yes a relativistic approach is used because the particle moves at the speed of light
The atmospheric pressure at normal conditions is equal to 10.33 m under water. Then 1.0mm mercury equals to
mm water.
Answer:13.6
Explanation:
Q1: A runner is jogging in a straight line at a steady vr= 6.8 km/hr. When the runner is L= 2.4 km from the finish line, a bird begins flying straight from the runner to the finish line at vb= 13.6 km/hr (2 times as fast as the runner). When the bird reaches the finish line, it turns around and flies directly back to the runner. What cumulative distance does the bird travel? Even though the bird is a dodo, assume that it occupies only one point in space (a “zero” length bird), travels in a straight line, and that it can turn without loss of speed. Answer in units of km. Q2: After this first encounter, the bird then turns around and flies from the runner back to the finish line, turns around again and flies back to the runner. The bird repeats the back and forth trips until the runner reaches the finish line. How far does the bird travel from the beginning (including the distance traveled to the first encounter)? Answer in units of km.
Answer:
Q1: 3.2km
Q2: 4.8K
Explanation:
Q1:
So db is the distance of bird, and dr is the distance of runner
db = 2vr and the distance of bird is going to be 2 times greater than the runner.
formulas: db = 2vr & db = 2dr
db = 2drL + (L - x) = 2x2L - x = 2x2L = 3xx = [tex]\frac{2}{3}[/tex]LInsert it in x = [tex]\frac{2}{3}[/tex]L
[tex]\frac{2}{3}[/tex](2.4km) = 1.6km
Now we use formula db = 2dr
db = 2L - xdb = 2(2.4km) - 1.6kmdb = 3.2kmQ2:
Formulas: Vr = L /Δt & Vb = db/Δt
Vr = L/ Δt ⇒ Δt = [tex]\frac{L}{Vr}[/tex][tex]\frac{2.4km}{6.8km/hr}[/tex][tex]\frac{6}{17}hr[/tex](Km cancel each other)
Vb = db/Δt ⇒ db = VbΔt13.6km/hr[tex](\frac{6}{17}hr )[/tex]4.8km(hr cancel each other)
Hope it helps you :)
A body is projected vertically upwards with a velocity of 10m/s from a vertically upward position at height h another body is dropped down at the same instant
Answer:
0.25 second
Explanation:
Given :
Velocity, v = 10 m/s
The height,
[tex]$ h = \frac{v^2}{2g} $[/tex]
[tex]$ h = \frac{10^2}{2\times 9.8} $[/tex]
= 5 m
Therefore the time at which both the bodies meet is
[tex]$ t = \frac{h}{v+v} $[/tex]
[tex]$ t = \frac{5}{10+10} $[/tex]
[tex]$ t = \frac{5}{20} = 0.25$[/tex]
So, time taken is 0.25 seconds
What is 1.2 kg converted into mg.
I need to know for step by step please?
=> 1200 000 mg
ExPlaNatIoN :We know that,
1 kg = 1000 g
1 g = 1000 gm
then,
1.2kg = 1.2 × 1000 g = 1200 g
1200 g = 1200 × 1000 mg
=> 1200 000 mghow can you separate salt from sand
dissolve salt in water then pour the liquid away from the sand and then evaporate the water to recover the salt
1. An arrow is shot with an initial velocity of 60.0 m/s at an angle of 30.0° above the horizontal. What is the maximum height it will reach?
a. 23 m
b. 46 m
c. 69 m
d. 92 m
2. A projectile is launched horizontally from a cliff with an initial speed of 40 m/s. The cliff is 125 m high and the projectile travels a horizontal distance of 200 m from the bottom of the cliff. What is the speed of the projectile right before it hits the ground?
a. 48 m/s
b. 52 m/s
c. 56 m/s
d. 60 m/s
e. 64 m/s
Answer:
46m
Explanation:
Given the following :
Initial Velocity (u) = 60
Angle(θ) = 30°
Maximum height it will reach?
The maximum height if a projection is calculated using the formula :
H = u²sin²θ / 2g
Where H = maximum height, g = acceleration due to gravity = 9.8m/s²
H = (60²sin × 0. 5²) / 2(9.8)
H = 900 / 19.6
H = 45.918m
H = 46m