The change in velocity of the train is 120 m/sec.
What is Velocity?The rate at which an object's position changes when observed from a specific point of view and when measured against a specific unit of time is known as its velocity. Unit of velocity is m/sec.
Given in the question train travels due south at 60 m/s. It reverses its direction and travels due north at 60 m/s,
We see that the change in direction of the train is 180 degree,
the net change in velocity is given as,
v = 60 m/s + 60 m/s
v = 120 m/s
A train travels due south at 60 m/s. It reverses its direction and travels due north at 60 m/s the change in velocity of the train is 120 m/sec.
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Find the electric field due to an infinite plane of positive charge with uniform surface charge density
Answer:
Explanation:
The Electric field due to an infinite plane of positive charge with uniform surface charge density can be derived a s follows
let us assume An infinite positively charged sheet and lets take a cylindrical gaussian surface on this surface which is perpendicular to this plane of sheet
we know that positive charge electric field lines will be perpendicular to this sheet surface will be perpendicular to the cylindrical surface
applying gauss law
[tex]Electric field * Area =[/tex] [tex]charge/epsilon\\[/tex]
also sigma=Q/A ⇒ Q=sigma*A
so on one face
E*A=sigma*A/epsilon
also we notice this electric field on one face of the sheet is exactly equal to that on the another face hence electric field will be twice
2E*A=sigma*A/epsilon
final result
[tex]E= sigma/2*epsilon[/tex]
Find the terminal velocity of a spherical bacterium (diameter ) falling in water. You will first need to note that the drag force is equal to the weight at terminal velocity. Take the density of the bacterium to be .
Complete Question
Find the terminal velocity of a spherical bacterium (diameter [tex]2.00 \mu m[/tex] ) falling in water. You will first need to note that the drag force is equal to the weight at terminal velocity. Take the density of the bacterium to be [tex]1.10 *10^{3} \ kg/m^3[/tex]
Answer:
The value is [tex]v_t = 2.38*10^{-6} \ m/s[/tex]
Explanation:
From the question we are told that
The diameter of the spherical bacterium is [tex]d = 2.0\mu m = 2.0 *10^{-6} \ m[/tex]
The density of the bacterium is [tex]\rho =1.10 *10^{3} \ kg/m^3[/tex]
Generally the radius is mathematically represented as
[tex]r = \frac{d}{2}[/tex]
=> [tex]r = \frac{2.0 *10^{-6}}{2}[/tex]
=> [tex]r = 1.0*10^{-6}[/tex]
Generally the volume is mathematically represented as
[tex]V = \frac{4}{3} * \pi * r^2[/tex]
=>[tex]V = \frac{4}{3} * 3.142 * (1.0*10^{-6})^3[/tex]
=>[tex]V = 4.189 *10^{-18} \ m^3[/tex]
Generally the mass is mathematically represented as
[tex]m = V * \rho[/tex]
=> [tex]m = 4.189 *10^{-12} * 1.10 *10^{3}[/tex]
=> [tex]m = 4.608 *10^{-15} \ kg[/tex]
Generally the terminal velocity is mathematically represented as
[tex]v_t = \frac{m * g}{ 6\pi * r * \eta}[/tex]
Here [tex]\eta[/tex] is the viscosity of water with value [tex]\eta = 1.005 *10^{-3} \ kg/m\cdot s[/tex]
So
[tex]v_t = \frac{4.608 *10^{-15} * 9.8}{ 6 * 3.142 *1.0*10^{-6} * 1.005 *10^{-3}}[/tex]
=> [tex]v_t = 2.38*10^{-6} \ m/s[/tex]
How much time is required for an airplane to reach its takeoff speed of 77m/a if it starts from rest and its average acceleration is 8.2m/s^2?
Answer:
The time required is t = 9.39 [s]
Explanation:
To solve this problem we must use the following equation of kinematics.
[tex]v_{f}=v_{o} +(a*t)[/tex]
where:
Vf = final velocity = 77 [m/s]
Vo = initial velocity = 0
a = acceleration = 8.2 [m/s²]
t = time [s]
The initial speed is zero, since the airplane begins its movement from rest. The initial speed is zero, since the aircraft begins its movement from rest. Another important fact is that the sign of acceleration is positive since the plane is accelerating, that is, its speed is increasing.
Now replacing:
77 = 0 + (8.2*t)
t = 9.39 [s]
How many atoms of each element are
needed to bond
Ca + F
k+ S
Li+ O
Answer:
How many electrons whill each element gain or lose in forming an ion? ... to form an ionic compound? a. Al and O b. H and N c. I and K d. F and Cl e. Li and S ... free flowing, but the valence electrons in ionic crystals have a strong bond with their atoms ... necessary to attain the electron configuration of what kind of element
Explanation:
what is the average speed of a student 100cm/s Bernard 150 cm/s Chloe 50 cm/s Dev 75 cm/s Eduardo 125cm/s
Answer:
100cm/s
Explanation:
Given the speed of the following students;
Bernard 150 cm/s
Chloe 50 cm/s
Dev 75 cm/s
Eduardo 125cm/s
Their average speed of a student will be the mean of their individual speed as shown:
Average speed = 150+50+75+125/4
Average speed = 400/4
Average speed = 100
Hence the average speed of a student is 100cm/s
A 10-kg object is hanging by a very light wire in an elevator that is traveling upward. The tension in the rope is measured to be 75 N. What are the magnitude and direction of the acceleration of the elevator
Answer:
2.31m/s² downwards
Explanation:
The sum of forces on the object is expressed as;
T-W
T is the tension on the rope
W is the weight
According yo Newton's second law:
T-W= ma
m is the mass
a is the acceleration
Given
T = 75N
W = mg = 10×9.81
W = 98.1N
Substitute
75-98.1 = 10a
-23.1 = 10a
a = -23.1/10
a = -2.31m/s²
The magnitude of the acceleration is 2.31m/s² and directions is downwards
25 POINTS FIRST CORRECT GET BRAINLIEST!!!!!!!!!!!!!!!!1
Answer:
carbon isnt 12
Explanation:
What role do planetesimals play in the origin of the planets?
The spacecraft that have visited the outer planets have all flown close to inner planets (Venus, for example), often more than once, as part of their journeys. What was the primary reason for this?
Answer:
1) The outer planets happened to have been on the far side of the sun, so the shortest route passes the inner planets
Explanation:
All the planets revolve around the sun in a circular orbital. The orbits of Mercury, Venus, Earth, and Mars are tightly held with sun as they are very close to the sun and revolve faster in comparison to outer planet Jupiter, Saturn, Uranus, and Neptune.
Because of the shortest distance between the sun and inner planets, the spacecraft is able to visit the inner planet more than once while outer planets are very far from the sun and revolve around a large orbit, so the spacecraft visited the outer planets less than the inner planet.
Hence, the correct answer is "1".
Which atoms are deflected the most by the magnetic field?
Answer:
Different ions are deflected by the magnetic field by different amounts. The amount of deflection depends on: the mass of the ion. Lighter ions are deflected more than heavier ones.
how much kinetic energy does a 2,000 kg car have when its traveling 5 m/s
Answer: 5000J
Explanation:
equation for kinetic energy is k=(mv^2)/2
plug in your mass and velocity
k = (2000*5^2)/2 = 5000J
Starting from rest, a 94-kg firefighter slides down a fire pole. The average frictional force exerted on him by the pole has a magnitude of 750 N, and his speed at the bottom of the pole is 3.1 m/s. How far did he slide down the pole
Given that,
Mass of a firefighter, m = 94 kg
Frictional force, F = 750 N
Speed at the bottom of the pole is 3.1 m/s
It is required to find the distance he slide down the pole.
Using Work-energy theorem,
initial potential energy = final kinetic energy + work done
[tex]mgh=W+\dfrac{1}{2}mv^2[/tex]
[tex]mgh=Fh+\dfrac{1}{2}mv^2[/tex]
Solving for h, such that :
[tex]h(mg-F)=\dfrac{1}{2}mv^2\\\\h=\dfrac{1}{2(mg-F)}mv^2\\\\h=\dfrac{1}{2(94(9.8)-750)}\times 94\times (3.1)^2\\\\h=2.63\ m[/tex]
So, he will slide 2.63 m down the pole.
A pilot wants to fly north. The plane has an air speed of
350 km/h. There is a 25 km/h wind blowing to the west.
(a) What is the plane's velocity relative to the ground?
(b)What is its heading?
Explain me in details. I’ll give u the brainliest if you give me the right answer.
Answer:
A? Cause is needs the Velocity more than the Heading.
Problem 9.20 A sphere of uniform density with mass 18 kg and radius 0.8 m is spinning, making one complete revolution every 0.4 s. The center of mass of the sphere has a speed of 8 m/s. (a) What is the rotational kinetic energy of the sphere
Answer:
K = 567.91 J
Explanation:
Given that,
Mass of sphere, m = 18 kg
Radius of a sphere, r = 0.8 m
It makes one complete revolution every 0.4 s.
The speed of center of mass of the sphere is 8 m/s
We need to find the rotational kinetic energy of the sphere. It is given by the formula as follows :
[tex]K=\dfrac{1}{2}I\omega^2[/tex]
I is moment of inertia,
[tex]I=\dfrac{2}{5}mr^2\\\\I=\dfrac{2}{5}\times 18\times (0.8)^2\\\\I=4.608\ kg-m^2[/tex]
[tex]\omega[/tex] is angular speed
[tex]\omega=\dfrac{2\pi }{0.4}\\\\=15.7\ rad/s[/tex]
So,
[tex]K=\dfrac{1}{2}\times 4.608\times (15.7)^2\\\\K=567.91\ J[/tex]
So, the rotational kinetic energy of the sphere is 567.91 J.
The rotational kinetic energy of the sphere is 710.8 J.
Moment of inertia of the sphereI = ¹/₂mr²
I = 0.5 x 18 x (0.8)²
I = 5.76 kgm²
Angular speed of the sphereω = 2πf
ω = 2π x (1/0.4s)
ω = 15.71 rad/s
Rotational kinetic energyK.E = ¹/₂Iω²
K.E = 0.5 x (5.76) x (15.71)²
K.E = 710.8 J
Thus, the rotational kinetic energy of the sphere is 710.8 J.
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You can't always see electromagnetic waves, but they are found throughout
the universe. There are only a few waves that are visible to the human eye.
Electromagnetic radiation is used to meet our needs and wants. It makes
important things — like medical imaging, reheating food and cell phones
possible. Radiation can be helpful for sending texts, but it's not always a
good thing. The sunburn you get sitting on the beach is caused by
electromagnetic radiation, too.
The author of this passage would most likely agree with which of the following
statements?
A
Scientists do not know very much about electromagnetic waves.
B
Electromagnetic radiation can be both helpful and harmful to humans.
с
People understand electromagnetic waves better than ocean waves.
D
Electromagnetic radiation is more harmful than it is helpful.
The author of this passage is focusing on both the merits and demerits of electromagnetic waves. Thus, he agree with the statement that electromagnetic radiation can be both helpful and harmful to humans.
What are electromagnetic waves?Electromagnetic waves are transformation of energy and they are travelling with a combined electric field and magnetic field. There are various kinds of electromagnetic waves namely, ultraviolet, radio waves, microwaves x-rays etc.
All these waves have significant applications in various fields. Mostly in medical fields. They are used for diagnosing, cancer treatments drug optimization etc.
However, these waves are highly energetic and harmful too. Direct and elongated exposure to these waves may cause severe health risks including cancer.
The author addresses the advantages and disadvantages of the electromagnetic waves. Thus, option B is correct.
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Does heat and temperature depend on the other or are they totally separate ideas? Explain.
Answer:
What heat means in thermodynamics, and how we can calculate heat using the heat ... Scientists define heat as thermal energy transferred between two systems
Explanation:
thermal energy
If a coil stays at rest in a very large static magnetic field, no emf is induced in this coil. Group of answer choices True False
Answer:
True
Explanation:
Faraday's Law says that there is a emf induced in a conductor when the vector flux of the magnetic field across it changes in time.This can be true due to one of two facts, either the magnitude of the magnetic field changes in time, or the area through which the flux occurs changes due to the movement of the object.In this case, due to the magnetic field is constant, and the coil stays at rest, there is no possible change in flux, so emf induced is zero.The magnetic dipole moment of Earth has magnitude 8.00 × 1022 J/T. Assume that this is produced by charges flowing in Earth's molten outer core. If the radius of their circular path is 3470 km, calculate the current they produce
Answer:
Explanation:
Dipole moment of a coil carrying current i with area A
M = i A , M is magnetic moment , i is current and A is area of the coil.
A = π R²
= 3.14 x ( 3470 x 10³ )²
= 3.78 x 10¹³ m²
8.00 x 10²² = 3.78 x 10¹³ x i
current i = 8.00 x 10²² / 3.78 x 10¹³
= 2.11 x 10⁹ A .
What best describes a bar magnet
Answer:Bar magnets are permanent magnets as opposed to electromagnets
Using five or more sentences, describe petroleum and what it is used for.
(I might mark brainliest if it is a good response) :D
Answer:
A liquid mixture of hydrocarbons that is present in certain rock strata and can be extracted and refined to produce fuels including gasoline, kerosen, diesal oil. :)
Explanation:
Yea mark brainleist pls
A solid sphere, with a mass of 3 kg, is rolling across a horizontal floor without slipping. The sphere has 8.4 J of total kinetic energy and has a center of mass velocity of 2 m/s. Calculate the rotational kinetic energy of the solid sphere.
Answer:
2.4 J
Explanation:
The total kinetic energy of the solid sphere = rotational kinetic energy + translational kinetic energy
KE(total) = KE(rot) + KE(trans)
KE(rot) = KE(total) - KE(trans)
Since its total kinetic energy KE' = 8.4 J and its mass, m = 3 kg and the velocity of its center of mass, v = 2m/s, KE(trans) = 1/2mv² = 1/2 × 3 kg × (2 m/s)² = 3 kg × 2 m²/s² = 6 kgm²/s² = 6 J
So, KE(rot) = KE(total) - KE(trans)
Substituting the values of the variables, we have
KE(rot) = 8.4 J - 6 J
KE(rot) = 2.4 J
So, the rotational kinetic energy of the solid sphere is 2.4 J
The rotational kinetic energy of the solid sphere will be "2.4 J".
Kinetic energyAccording to the question,
Total Kinetic energy, KE' = 8.4 J
Mass, m = 3 kg
Center of mass's velocity, v = 2 m/s
Now,
KE(trans) = [tex]\frac{1}{2}[/tex]mv²
By substituting the values,
= [tex]\frac{1}{2}[/tex] × 3 × (2)²
= [tex]\frac{1}{2}[/tex] × 3 × 4
= 6 kgm³/s² or,
= 6 J
We know the relation,
→ KE(rot) = KE(total) - KE(trans)
By putting the values,
= 8.4 - 6
= 2.4 J
Thus the approach above is correct.
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A woman runs up a flight of stairs. The gain in her gravitational potential energy is U. If she runs up the same stairs with twice the speed, what is her gain in potential energy?
Answer:
U
Explanation:
The change in gravitational potential energy only depends of the difference in height (in this case the number of stairs), so as the height remained the same, her gain in potential energy remained the same, independent from her climbing speed.Use the drop-down menus to identify the parts of the diagram labeled A, B, and C.
Label A
Label B
Label C
Answer:
b
Explanation:
bcuz I looked it up and it was on there
Answer:
the answers are:
- cool fluid sinks
- warm fluid rises
- convention current
Explanation:
Im late but mark me as brainliest for helping you out cause the one on top is clueless
the weight of a box having a mass of 100kg is blank N.
Answer:
What is the answer we are supposed to be finding?
Explanation: Your answer is 980.7 if you are converting kilograms to Newtons
A 11.8-kg cylinder rolls without slipping on a rough surface. At an instant when its center of gravity has a speed of 10.4 m/s, determine the following. (a) the translational kinetic energy of its center of gravity J (b) the rotational kinetic energy about its center of gravity J (c) its total kinetic energy J
Answer:
1. 638.144j
2. 319.072 j
3. 957.216 j
Explanation:
M = 11.8 kg cylinder
V = speed of center of gravity = 10.4m/s
A.
Translational kinetic energy
= 1/2mv²
1/2x 11.8kg x 10.4²
= 11.8x108.16/2
= 1276.288/2
= 638.144 J
This is the translational energy
B.
Rotational energy
1/2Iw²
I = mv²/2
w = v/r
When we substitute
1/2[mv²/2][v/r]²
= 1/4mv²
= 1/4 x 11.8 x 10.4²
= 1276.288/4
= 319.072
This is the rotational energy
C
Total kinetic energy.
We add the values of A and B above to get this.
638.144 J + 319.072 J
= 957.216J
The exchange of oxygen and carbon dioxide takes place through the capillary wall.
True
False
Explanation:
It mainly flows blood to arteries of heart but the answer is true.. because it also exchange oxygen,nutrient etc..
Anybody good at science math?
Answer:
the pressure is: 200 N/m^2
Explanation:
Recall that pressure is defined as force (F) per unit of area (A), which in math terms is:
P = F / A
Then, if the force is 2.4 N , and the area of the glass' bottom is 0.012 m^2, then the pressure is:
P = 2.4 / 0.012 = 200 N/m^2
Answer:PLEASE HELP ME
Explanation:
what is it? and explain pls
The velocity at which an object is sent moving and the mass of the object both play a hand in the level of kinetic energy that object produces. Mass and kinetic energy have a positive relationship, which means that as mass increases, kinetic energy increases, if all other factors are held constant.
11.
A current of 67 amps runs through a resistor of 37 ohms, how much voltage is lost?
A centrifuge in a medical laboratory rotates at an angular speed of 3,550 rev/min. When switched off, it rotates through 52.0 revolutions before coming to rest. Find the constant angular acceleration (in rad/s2) of the centrifuge.
Answer:
-62.02πrads/sec^2
Explanation:
A centrifuge in a medical laboratory rotates at an angular speed of 3,550 rev/min. When switched off, it rotates through 52.0 revolutions before coming to rest. Find the constant angular acceleration (in rad/s2) of the centrifuge.
We need to convert to SI unit
9.549rev/ min= 1rad/sec
Then to convert angular speed of 3,550 rev/min to rad/sec
( 1 rad/sec)/9.549rev/min = x/5600rev/min
Then
(3,550 rev/min)/(9.549rev/min)= 371.77rad/sec
=118.4πrad/sec
6.823rad= 1rev
52.0 revolutions = 52×6.823= 354.796rads
= 113πrads
We will use expresion below to calculate our angular acceleration
w^2 - w^2(0)= 2α¢
Where w= angular speed
w(0)= initial angular
If final angular speed= 0
α=-w^2(0)/2¢
α=(-118.4π)^2/(2×113)
=-14018.56/226
-62.02πrads/sec^2