Answer:
d) 105 s
Explanation:
Given the following data;
Distance A (length of train) = 100 m
Velocity = 72 km/h to meters per seconds = 72 * 1000)/3600 = 72000/3600 = 20 m/s
To find the time;
Time = distance/speed
Time = 100/20
Time = 5 seconds.
II. When the distance (bridge) is 2km;
Distance B = 2km = 2*1000 = 2000 meters
Time = distance/speed
Time = 2000/20
Time = 100 seconds
Therefore, total time = 5 + 100 = 105 seconds
A plastic rod becomes negatively charged when it is rubbed with a piece of wool. How does the rod become charged?
Electrons move from the rod to the wool.
Protons move from the rod to the wool.
Electrons move from the wool to the rod.
Protons move from the wool to the rod.
Electrons move from the wool to the rod.
BEcause if they move from wool to rod, the rod has more number of electrons now. Hence making it negatively charged
The plastic rod becomes charged when electrons move from the wool to the rod to become negatively charged. Details about charge can be found below.
What is electronegativity?Electronegativity is the tendency, or a measure of the ability, of an atom or molecule to attract electrons and thus form bonds.
According to this question, a plastic rod becomes negatively charged when it is rubbed with a piece of wool.
An atom becomes negatively charged when it gains electrons from another atom, hence, it can be said that the plastic rod becomes charged when electrons move from the wool to the rod to become negatively charged.
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b) The ice cube melting on the nonconducting plate
Is it conduction,convention, or radiation thermal energy
Answer:I think it’s convection
Explanation:
This a solving question
Please please help
Answer:
Part A
The sound intensity at the location 150 from the firework = 4.3[tex]\overline 5[/tex] W/m²
Part B
The power the firework is emitting is approximately 1,231.5 kW
Explanation:
Part A
The data of the firework sound heard by the two friends are;
Let 'A' represent the location of the friend at a point 150 m from the fireworks and let 'B' represent the location of the friend watching from a distance of 700 m from the firework
The distance of 'A' from the sound, r₁ = 150 m
The distance of 'B' from the sound, r₂ = 700 m
The intensity at which 'B' hears the sound, I₂ = 0.2 W/m²
The relationship between sound intensity and distance is given as follows;
[tex]\dfrac{I_2}{I_1} = \left (\dfrac{r_1}{r_2} \right )^2[/tex]
[tex]\therefore {I_1} = \dfrac{I_2}{ \left (\dfrac{r_1}{r_2} \right )^2} = I_2 \times \left (\dfrac{r_2}{r_1} \right )^2[/tex]
Plugging in the values gives;
[tex]\therefore {I_1} = 0.2 \times \left (\dfrac{700}{150} \right )^2 = \dfrac{196}{45} = 4.3\overline 5[/tex]
The sound intensity at location 'A', I₁ = 4.3[tex]\overline 5[/tex] W/m²
Part B
The relationship between power, 'P', and intensity, 'I', is presented as follows;
[tex]I = \dfrac{P}{4 \cdot \pi \cdot r^2}[/tex]
P = I·4·π·r² = 4·I·π·r²
Therefore, at point 'A', where the distance, r₁ = 150 m, and the intensity, I₁ = 4.3[tex]\overline 5[/tex] W/m², we have;
P = 4 × 4.3[tex]\overline 5[/tex] W/m² × π × (150 m)² = 1231504.32021 W
The power the firework is emitting, P ≈ 1,231.5 kW.
Define and describe the following terms: amplitude, wavelength, frequency, period, tension.
Answer:
Amplitude—distance between the resting position and the maximum displacement of the wave
Frequency—number of waves passing by a specific point per second
Period—time it takes for one wave cycle to complete
wavelength λ - the distance between adjacent identical parts of a wave, parallel to the direction of propagation.
Tension - described as the pulling force transmitted axially by the means of a string, a cable, chain, or similar one-dimensional continuous object, or by each end of a rod, truss member, or similar three-dimensional object
On your first trip to Planet X you happen to take along a 100 g mass, a 40-cm-long spring, a meter stick, and a stopwatch. You're curious about the free-fall acceleration on Planet X, where ordinary tasks seem easier than on earth, but you can't find this information in your Visitor's Guide. One night you suspend the spring from the ceiling in your room and hang the mass from it. You find that the mass stretches the spring by 22.6 cm . You then pull the mass down 10.9 cm and release it. With the stopwatch you find that 10 oscillations take 18.8 s .
Answer:
[tex]g=2.513m/s^2[/tex]
Explanation:
From the question we are told that:
Mass Taken [tex]m=100g \approx 100*10^{-3}[/tex]
Strain on Spring [tex]l_s=22.6cm \approx 22.6*10^{2}[/tex]
Distance pulled down [tex]d_d=10.9[/tex]
Time for ten oscillations take [tex]t=18.8s[/tex]
Generally the equation for angular velocity is mathematically given by
[tex]\omega=2\pi\\\omega=2\pi*\frac{10\ oscillations}{t}\\\\\omega=2\pif=2\pi*\frac{10\ oscillations}{18.8}\\Also\\\omega=\sqrt{\frac{k}{m}} \\\omega=\sqrt{\frac{k}{100*10^{-3}}}[/tex]
Therefore
[tex]{2\pi*\frac{10\ oscillations}{18.8}}=\sqrt{\frac{k}{100*10^{-3}}} \\k=\sqrt{2\pi*\frac{10\ oscillations}{18.8}}*100*10^{-3}\\k=1.112N/m[/tex]
Generally the equation for Acceleration due to gravity is mathematically given by
[tex]F=mg\\mg=k l_s\\g=\frac{k l_s}{m}\\g=\frac{1.112*2.6*10^{2}}{100*10^{-3}}[/tex]
[tex]g=2.513m/s^2[/tex]
If a document is to be produced using a duplicating
camera, where should the camera be placed in or
der to obtain an exact copy? A. at the point which
is twice the focal lenght of the lens of the camera
B. at the optical centre of the lens of the camera C
between the principal and a point twice the foca
lens of the lens of the camera D. beyond a poin
twice the focal lenght of the lens of the camera
Answer: A. at the point which
is twice the focal lenght of the lens of the camera
Explanation:
When a certain document is to be produced through the use of a duplicating camera, it should be noted that the camera should be placed at the point which is twice the focal lenght of the lens of the camera so as to get the exact copy of the document.
It should be noted that placing the camera between the principal and a point twice the focal lens of the camera lens or beyond a point that's twice the focal length will not produce the document.
Therefore, the correct option is A
Can someone please, please help me out here? I understand literally none of this, despite watching multiple videos and reading a few articles on Kirchoff's laws.
Answer:
Explanation:
By Kirchoff's laws, I1 + I2 = 3
I2 = 3 - I1
Following circuit on the left, V = summation of IRs
9 = I1*3 + 3*2
3*I1 = 9 - 6 = 3
I1 = 1A
I2 = 3 -1 = 2A
Following circuit on the right, V = summation of IRs
ε = I2*4.5 + 3*2
= 2*4.5 + 6
= 15V
Which of the following statements best explains the relationship between the common property regime and energy distribution? The common property regime ____.
may lead to inequitable availability of energy resources or, worse, scarcity
is the direct result of energy security
regime will provide energy security
will prevent energy scarcity
Answer:
the anser is B
Explanation:
A fall thrown vertically upwards with a speed
of 20 ms-¹ from the top of a tower reaches
the earth in 8seconds. find the height of the
tower.
take g= 10ms-²
Answer:
Height of tower = 480 meter
Explanation:
Given:
Initial velocity = 20 m/s
Time taken to reach ground = 8 second
So,
Final velocity = 0 m/s
Acceleration due to gravity = 10 m/s²
Find:
Height of tower
Computation:
s = ut + (1/2)(g)(t)²
s = (20)(8) + (1/2)(10)(8)²
s = 160 + (1/2)(10)(64)
s = 160 + (10)(32)
s = 160 + 320
s = 480 meter
Height of tower = 480 meter
A Cathode of initial mass 10.00g weigh to 10.05g
after a Current of SA passes through the voltmeter of 10 minutes - Calculate the E.C.E of the metal deposed
Answer:
i'm sorry i'm not a physics student
Which is equivalent to 1 W?
Answer:
1 joule per second.
Explanation:
The watt (symbol: W) is a unit of power or radiant flux. In the International System of Units (SI), it is defined as a derived unit of (in SI base units) 1 kg⋅m2⋅s−3 or, equivalently, 1 joule per second.
What is the difference in intensity for two sounds that are 40 dB apart?
the difference of 10 dB is considered as having 10 times the intensity, so difference of 40 dB means :
=》10 × 10 × 10 × 10
=》10000 times
so the the intensity of one sound is 10000 times the other one.
Starting from the results of Examples 5.4 and 5.5, estimate the number of cubic meters of water that would flow each second through an OTEC plant large enough ( 1000 M W e 1000 MWe) to provide electricity for Miami. Use the approximation of an ideal heat engine as in the examples. If this water flows at a velocity of 4 m / s 4 m/s, what would be the necessary diameter of the pipes?
Answer: Hello Results of examples 5.4 and 5.5 are missing from your question but I was able to find it online and use it to resolve your question
answer :
a) 1780 m^3/sec
b) 23.81 m
Explanation:
a) calculate the number of m^3 of water flowing through an OTEC plant charge
assumption : assuming an ideal heat engine
Q / t = m*c*∆T * (eff) / t
1e^9 J/s = 1g/cc *V(1cal/g°C) * 2°C (6.7%)*(4.184J/cal) / t
Hence: V / t ( number of m^3 of water ) = 1.78e^9 cc / sec = 1.78 * 10
= 1780 m^3/sec
b) Determine the diameter of pipes
Given that the water flows at 4m/s ( velocity )
1780 m^3 /sec = A * V ------ ( 1 )
A = π*d^2/4 = 1780 / 4 = 445 m^2 -------- ( 2 )
v = 4 m/s
Back to equation 2
d^2 = ( 445 * 4 ) / π
≈ 567
∴ necessary diameter ( d ) = [tex]\sqrt{567}[/tex] = 23.81 m
Need some physics gel pls
The flow of electrons in a circuit follows a path from the negative terminal of the battery to the positive terminal
Answer:
No it's not true electric grow from Positive terminal to negative terminal
It takes 8.76 hours to travel 427 miles Northwest from Chicago, Illinois to Minneapolis, Minnesota. What is your velocity for the trip?
Answer:
infinity
Explanation:
this is because time is irrelevant
A 0.7 tennis ball is thrown with a velocity of 20 m second to the right what is the momentum of the tennis ball
Explanation:
Momentum of an object is defined as the product of the mass of object and the velocity with which it is moving.
p = mv
where, p = momentum, m= mass and v= velocity
mass m = 0.7 Kg and v = 20 m/s
p = 0.7×20 = 14 Kg-m/sec
Therefore, momentum of the object = 14 kg-m
The Voltmeter reads 16 V. The ammeter reads 0.25 A. The resistance must be
Answer:
64 ohms =R
Explanation:
R is directly proportional to V
R is inversely proportional to I(Current
2. Before 0.5-kg ball is dropped from a third story window 20 m above the sidewalk. What is the potential
energy of the ball?
a. 4 J
b. 9800 J
C. 98 J
d. 150 J
Answer:
C
Explanation:
C
20*9.8*0.5
98
please help me out i'm so depressed and such a failure
how does the brightness of the lamp (L) vary if we dispalce the cursor (C) of the rheostat
a)Towards A
b) Towards B
Answer:
ok so first ur not a failure and its okay don't be so hard on ur self
<3Which three statements describe electromagnetic waves?
Answer:
It is most likely option A B and C
Answer:
I think option A ,B,D are correct
A 5kg block is pulled across the table by a force of 61N. Calculate the acceleration of the object.
Answer:
a = 12.2 m/s²
Explanation:
Given: 5 kg, 61N
To find: Acceleration (a)
Solution:
A = F ÷ m
= 61 ÷ 5
= 12.2 m/s²
Newtons are derived units, equal to 1 kg-m/s². In other words, a single Newton is equal to the force needed to accelerate one kilogram one meter per second squared.
What words go in the missing blanks?
An object with less ____ and ____. Will be easier to move.
most of the foods we eat are acid or base or neutral.
Answer:Acidic: meat, poultry, fish, dairy, eggs, grains, alcohol. Neutral: natural fats, starches, and sugars. Alkaline: fruits, nuts, legumes, and vegetables.
Explanation:
The diagrams show two planets of different masses with identical orbiting satellites. Select all the conditions that would increase the gravitational force between each pair.
A. move the satellites closer to the planet
B. move the satellites farther from the planet
C. Add mass to the satellites
D.Remove mass from the satellites
Answer:
C I think but I'm not sure
Explanation:
Because by adding mass it would add more gravitational pull
A roller coaster speeding down a hill is an example of
A. Increasing kinetic energy
B. Increasing nuclear energy
C. All of these choices
D. Increasing in potential energy
Answer:
If I'm not wrong; I think the answer is A
Explanation:
A. Increasing kinetic energy
When a substance is poured from one container to another, its shape changes but its volume does not, what state of matter is the substance in?
A. Plasma
B. Liquid
C. Gas
D. Solid
Answer: When a liquid substance is poured into a vessel, it takes the shape of the vessel, and, as long as the substance stays in the liquid state, it will remain inside the vessel. Furthermore, when a liquid is poured from one vessel to another, it retains its volume (as long as there is no vaporization or change in temperature) but not its shape.
Explanation: A solid has a definite shape and volume. A liquid has a definite volume, but takes the shape of its container. A gas lacks either a defined shape or volume. Plasma is similar to a gas in that its particles are very far apart, but a gas is electrically neutral and plasma has a charge.
Answer:
B
Explanation:
Liquid
What is the total resistance of the circuit shown below?
Two-resistor parallel circuit
A. 50 ohms
B. 30 ohms
C. 25 ohms
D. 12 ohms
HELP
Answer:
D. 12Explanation:
I just did the Gizmo and the correct answer is 12 :) Hope this helps!
The total resistance of the circuit for parallel resistors of 41 Ω and 17 Ω is 12Ω. Hence option D is correct.
What is a parallel and series combination of resistance?When two or more resistors are connected between two same points, they are said to be connected in parallel combination(as shown in fig). The equivalent resistance is the reciprocal and the sum of reciprocals of all resistance connected in parallel combination.
[tex]\frac{1}{R_{s}} = \frac{1}{R_{1}} + \frac{1}{R_{2} } + \frac{1}{R_{3}} ..........+ \frac{1}{R_{n} }[/tex] where Rs is the equivalent or total resistance of the circuit.
In parallel combination, same potential difference exists across each resistor. But current through each resistance is different.
When two or more resistors are connected one after other, they are said to be connected in series as shown in figure. in this combination voltage difference across each resistance is different which is given by ohms law. current flowing through each resistance is same.
equivalent resistance for series combination is given by,
R(s) = R₁ + R₂ + R₃...........+R(n).
In this problem given resistance are not seen, Resistor can be with 41 and 17Ω.
Given,
R₁ = 17 Ω
R₂ = 41 Ω
[tex]R_{s} = ?[/tex]
by parallel combination,
[tex]\frac{1}{R_{s}} = \frac{1}{R_{1} } + \frac{1}{R_{2} }[/tex]
[tex]R_{s} = \frac{R_{1} R_{2} }{R_{1} + R_{2} }= \frac{17*41}{17+41} = \frac{697}{58} = 12[/tex]
R = 12 Ω.
Hence option D is correct.
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On Earth, the gravitational Field strength is much than on the moon. If a piece of rock was taken from the Moon to the Earth, state what change, if any, there would be in mass, weight and density of the rock.
1. Mass
2. Weight
3. Density
What way is more effective when trying to make magnets repel further/faster, using strong magnets over weak magnets or putting the magnets closer together?
Answer:
north pole of a magnet repels the north pole of another magnet no matter of their shape , size , weakness , strength ,etc .
Explanation: