A train travels between two stations that are 63 km apart at an average speed of 35 m/s. Time taken by train after leaving the first station and arrive at the second station 1.8 sec.
What is speed?The speed of an object is the magnitude of the change of its position over time or the magnitude of the change of its position per unit of time; it is thus a scalar quantity.
time = Distance / speed
= 63/35.
= 1.8 sec
A train travels between two stations that are 63 km apart at an average speed of 35 m/s. Time taken by train after leaving the first station and arrive at the second station 1.8 sec.
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Could a sea breeze occur at night? Explain why or why not.
The amount of energy a substance has depends on the state of matter
the substance is in at the time.
True
or False
A person is standing on a level floor. His head, upper torso, arms, and hands together weigh 458 N and have a center of gravity that is 1.34 m above the floor. His upper legs weigh 120 N and have a center of gravity that is 0.766 m above the floor. Finally, his lower legs and feet together weigh 89.8 N and have a center of gravity that is 0.204 m above the floor. Relative to the floor, find the location of the center of gravity for the entire body.
Answer:
the location of the center of gravity for the entire body is 1.08 m
Explanation:
Given the data in the question;
w1 = 458 N, y1 = 1.34 m
w2 = 120 N, y2 = 0.766 m
w3 = 89.8 N, y2 = 0.204 m
The location arrangement of the body part is vertical, locate the overall centre of gravity by simply replacing the horizontal position x by the vertical position y as measured relative to the floor.
so,
[tex]Y_{centre of gravity}[/tex] = (w1y1 + w2y2 + w3y3 ) / ( w1 + w2 + w3 )
so we substitute in our values
[tex]Y_{centre of gravity}[/tex] = (458×1.34 + 120×0.766 + 89.8×0.204 ) / ( 458 + 120 + 89.8 )
[tex]Y_{centre of gravity}[/tex] = 723.9592 / 667.8
[tex]Y_{centre of gravity}[/tex] = 1.08 m
Therefore, the location of the center of gravity for the entire body is 1.08 m
Which factors affect the gravitational force between two objects?
-
distance and velocity
O mass and distance
O mass and weight
acceleration and weight
TELE
Answer:
mass and distance
Explanation:
mass, and distance. The force of gravity depends directly upon the masses of the two objects, and inversely on the square of the distance between them.
I need help with this, I can't figure it out.
Here is the link:
https://platform.breakoutedu.com/game/play/fun-in-the-sun-140559-XMWCQF1LPL
Answer:
Star, Triangle, Circle, Rhombus, Square.Left, Down, Right, Down, Up.2,3,2,4.L,O,O,K,I,N,G,F,L,Y.Explanation: You're welcome ✓
ELE Review questions
POSSIBLE POINTS: 3
Match the energy transformation sequence with the device it describes:
A hair dryer plugged into the wall
a
A hand crank generator emergency radio
A battery operated fan
11 CE to ELE
+ ELE to KE
:: KE to ELE
h
1
2
A Review
Answer:
1. ELE to KE = Electrical energy conversion to kinetic energy.
2. KE to ELE = kinetic energy conversion to electrical energy.
3. CE to ELE = chemical energy conversion to electrical energy.
Explanation:
The Law of Conservation of Energy states that energy cannot be destroyed but can only be transformed or converted from one form to another.
Some examples of energy are chemical energy, electrical energy, kinetic energy, sound energy, potential energy, light energy, etc.
The transformation of energy from one form to another are described below;
1. A hair dryer plugged into the wall: it involves the conversion of electrical energy to kinetic energy. The energy type present in the wall socket is electrical energy which powers the hair dryer to have kinetic energy i.e the energy possessed due to motion of hair dryer.
2. A hand crank generator emergency radio: it illustrates the conversion of kinetic energy to electrical energy. The hand crank generator possess kinetic energy as it is being wounded before it is then converted into electrical energy which powers the radio.
3. A battery operated fan: it illustrates the conversion of chemical energy to electrical energy. The cells present in battery possess chemical energy that is being converted into electrical energy to power the fan.
Which sentence is correct?
Answer:
pretty sure its B if it isnt im so so sorry
Explanation:
a virtual image is formed by
a) simple microscope b) telescope c) the ordinary camera d) a slide projector in a cinema hall
Answer: ordinary camera
Explanation:
Answer:
C.
Explanation:
How does the energy in a system of magnets change when two magnets repel and move away from each other
if a wave passes every 17.4 seconds, what is the frequency?
Answer:
to be completely honest I have no idea however I tried calculating it on a calculator and umm...
I think the frequency is...
17,229,452
but ya know I could be totally wrong so if I am sorry
An unfortunate astronaut loses his grip during a spacewalk and finds himself floating away from the space station, carrying only a rope and a bag of tools. First he tries to throw a rope to his fellow astronaut, but the rope is too short. In a last ditch effort, the astronaut throws his bag of tools in the direction of his motion, away from the space station. The astronaut has a mass of ma=102 kgma=102 kg and the bag of tools has a mass of mb=10.0 kg.mb=10.0 kg. If the astronaut is moving away from the space station at vi=2.10 m/svi=2.10 m/s initially, what is the minimum final speed vb,fvb,f of the bag of tools with respect to the space station that will keep the astronaut from drifting away forever?
Answer:
The answer is "[tex]2.352 \ \frac{m}{s}[/tex]"
Explanation:
[tex]\to mass(m_1)=102 \ kg\\\\\to mass(m_2)=10 \ kg \\\\\to v=2.10\ \frac{m}{s}\\\\[/tex]
momentum before:
[tex]\to p=(m_1+m_2)v[/tex]
[tex]=(102+10)2.10\\\\=(102\times 2.10 +10 \times 2.10)\\\\=214.2+21\\\\=235.2[/tex]
momentum After:
[tex]\to p=(m_1+m_2)v[/tex]
[tex]=(102\times 0 +10 \times v)\\\\ =(0 +10v)\\\\=10v\\[/tex]
Calculating the conservation of momentum:
[tex]\to \text{momentum before = momentum After}[/tex]
[tex]\to 235.2=10v\\\\\to v= \frac{235.2}{10}\\\\ \to v=2.352 \ \frac{m}{s}[/tex]
A pendulum Bob released from some initial height such that the speed of the bob at the bottom of the swing is 1.9m/s. What is the initial height of the bob?
Answer:
h = 18.4 cm
Explanation:
Given that,
The speed of the bob at the bottom of the swing is 1.9m/s.
We need to find the initial height of the bob. Let it is h.
We can find it using the conservation of energy i.e.
[tex]mgh=\dfrac{1}{2}mv^2[/tex]
Where
v is speed of the bob
So,
[tex]h=\dfrac{v^2}{2g}\\\\h=\dfrac{(1.9)^2}{2\times 9.8}\\\\h= 0.184\ m[/tex]
or
h = 18.4 cm
So, the initial height of the bob is 18.4 cm.
The initial height of bob will be "18.4 cm".
Speed and height:Speed would be the scalar quantity that describes "how quickly an attribute moves." This could sometimes be defined as this same rate whereby an object travels a given distance.
According to the question,
The speed of the bob = 1.9 m/s
Let,
The initial height be "h".
By using the conservation of energy, we get
→ mgh = [tex]\frac{1}{2}[/tex]mv²
or,
→ h = [tex]\frac{v^2}{2g}[/tex]
By substituting the values, we get
= [tex]\frac{(1.9)^2}{2\times 9.8}[/tex]
= 0.184 m or,
= 18.4 cm
Thus the above answer is correct.
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why don't we draw lewis dot diagrams for nobel gases
Which list below contains only ionic compounds?
A. CaCl2, H2O, LIF
B. CO2, K20, P4010
C. LiF, CaCl2, Mgo
D. NO2, Mgo, CuCl2
Answer:
C. LiF, CaCl2, MgO
Explanation:
Ionic compound: It is that compound which consist of negative and position ions and held together by electrostatic force of attraction.
The ionic compound is neutral.
The ionic compound formed between metal and non-metal.
Covalent compound: It is that compound in which sharing of electrons between two atoms occur.
A.[tex]CaCl_2,H_2O,LiF[/tex]
H2O is not ionic compound. It is polar covalent.
Therefore, it does not contain only ionic compounds.
B.CO2,K2O,P4O10
CO2 and P4O10 are not ionic .It is covalent.
Therefore, it does not contain only ionic compounds.
C. LiF,CaCl2 ,MgO
All compounds are ionic because in given compounds one ion is negative and one is metal (positive).
Therefore, it contains only ionic compounds.
D.NO2,MgO,CuCl2
NO2 is not ionic.
Therefore, it does not contain only ionic compounds.
Option C is correct.
6th grade science I mark as brainliest (can someone answer my other question like this?)
Answer:A: July
B: July and august
C:true
Explanation:
A positively charged particle of mass 7.2 x 10-8 kg is traveling due east with a speed of 88 m/s and enters a 0.6-T uniform magnetic field. The particle moves through one-quarter of a circle in a time of 2.2 x 10-3 s, at which time it leaves the field heading due south. All during the motion the particle moves perpendicular to the magnetic field. Determine the magnitude of its charge in mC. (1 mC
Answer:
q = 8.57 10⁻⁵ mC
Explanation:
For this exercise let's use Newton's second law
F = ma
where force is magnetic force
F = q v x B
the bold are vectors, if we write the module of this expression we have
F = qv B sin θ
as the particle moves perpendicular to the field, the angle is θ= 90º
F = q vB
the acceleration of the particle is centripetal
a = v² / r
we substitute
qvB = m v² / r
qBr = m v
q =[tex]\frac{m\ v}{B\ r}[/tex]
The exercise indicates the time it takes in the route that is carried out with constant speed, therefore we can use
v = d / t
the distance is ¼ of the circle,
d = [tex]\frac{1}{4} \ 2\pi r[/tex]
d =[tex]\frac{\pi }{2r}[/tex]
we substitute
v = [tex]\frac{\pi r}{2t}[/tex]
r = [tex]\frac{2 \ t \ v}{\pi }[/tex]
let's calculate
r =[tex]\frac{2 \ 2.2 \ 10^{-3} \ 88}{\pi }[/tex] 2 2.2 10-3 88 /πpi
r = 123.25 m
let's substitute the values
q = [tex]\frac{ 7.2 \ 10^{-8} \ 88}{ 0.6 \ 123.25}[/tex]7.2 10-8 88 / 0.6 123.25
q = 8.57 10⁻⁸ C
Let's reduce to mC
q = 8.57 10⁻⁸ C (10³ mC / 1C)
q = 8.57 10⁻⁵ mC
Suppose you have a cylinder filled with diatomic oxygen (O2) and it is running low. The cylinder is shown above, is made of steel, and has a fixed volume of 10 L.
You are asked to determine the number of O2 molecules that are left in the cylinder, so you take a measurement of the temperature to be 20℃. You then note that the pressure gauge reads 100 psi, which you checked at sea level in Bellingham, where the local pressure is one atm (14.7 psi). Calculate the number of O2 molecules left in the container.
Answer:
The number of O₂ molecules that are left in the cylinder is 1.70x10²⁴.
Explanation:
The number of oxygen molecules can be found using the Ideal Gas law:
[tex] PV = nRT [/tex]
Where:
P: is the pressure = 100 psi
V: is the volume = 10 L
n: is the number of moles =?
T: is the temperature = 20 °C = 293 K
R: is the gas constant = 0.082 L*atm/(K*mol)
Hence, the number of moles is:
[tex]n = \frac{PV}{RT} = \frac{100 psi*\frac{1 atm}{14.7 psi}*10 L}{0.082 L*atm/(K*mol)*293 K} = 2.83 moles[/tex]
Now, the number of molecules can be found with Avogadro's number:
[tex]n_{m} = \frac{6.022 \cdot 10^{23}\: molecules}{1\: mol}*2.83 moles = 1.70 \cdot 10^{24} \: molecules[/tex]
Therefore, the number of O₂ molecules that are left in the cylinder is 1.70x10²⁴.
I hope it helps you!
when the body said to be in equilibrium
Answer:
Oh! I just learned abt this
Explanation:
the body is said to be in equilibrium if it is resting or moving with uniform velocity.
Answer: The body is said to be in balance if it is at rest or moving at a uniform speed. In other words, if the body's linear and angular acceleration is zero, the body is said to be in balance. 1