Answers
Answer:
1. (a) The final velocity is 20 m/s
(b) The distance travelled is20 meters
2. The distance travelled by the train in the 30 seconds is 825 meters
3. The most correct option is;
(d) 53 km
4. The heat, developed by the electric iron is 15,000 joules
5. a) In the first network the resistance between A and B is 2 Ω
b) In the second network the resistance between A and B is 4Ω
c) In the third network the resistance between A and B is 6Ω
d) In the fourth network the resistance between A and B is 2Ω
Explanation:
1. (a) The parameters of the cheetahs motion are;
The initial motion (velocity) of the cheetah = 0 m/s (The cheetah starts from rest)
The acceleration of the cheetah, a = 2 m/s²
The duration of the acceleration of the cheetah, t = 10 seconds
The kinematic equation of the motion of uniform acceleration, of the cheetah can be written in the following form;
v = u + a·t
s = u·t + 1/2·a·t²
Where;
v = The final velocity
u = The initial velocity = 0 m/s
a = The acceleration of the cheetah = 2 m/s²
s = The distance traveled
∴ v = 0 + 2 × 10 = 20
The final velocity, v = 20 m/s
(b) From s = u·t + 1/2·a·t², we have;
s = 0 × 10 + 1/2 × 10 × 2² = 20
The distance travelled, s = 20 meters
2. The given details of the motion of the train are;
The initial velocity of the train, u = 20 m·s⁻¹
The acceleration of the train, a = 0.5 m·s⁻²
The duration of the train's acceleration, t = 30 seconds
Therefore, the distance travelled, 's', is given by; s = u·t + 1/2·a·t²
∴ s = 20 × 30 + (1/2) × 0.5 × 30² = 825
The distance travelled by the train in the 30 seconds, s = 825 meters
3. The given distance the truck covers with the average speed of 80 km/h, d₁ = 40 km
The distance the truck then covers with the average speed of 40 km/h, d₂ = 40 km
[tex]Average \ speed = \dfrac{Total \ distance}{Time}[/tex]
[tex]\therefore time, \, t = \dfrac{Total \ distance}{Average \ speed}[/tex]
The time it takes the truck to cover the 40 km at 80 km/h = 40 km/(80 km·h) t₁ = 0.5 hour
The time it takes the truck to cover the 40 km at 80 km/h = 40 km/(40 km·h) t₂ = 1 hour
The total time taken to cover both 40 km distances, t = t₁ + t₂
∴ The total time taken to cover both 40 km distances, t = (0.5 + 1) hour = 1.5 hours
The total distance covered at both speeds, d = d₁ + d₂
∴ d = 40 km + 40 km = 80 km
The average speed of the truck for the total distance, [tex]v_{average}[/tex] = d/t
∴ [tex]v_{average}[/tex] = 80 km/1.5 hours = 53.[tex]\overline 3[/tex] km/h ≈ 53 km/h
The average speed of the truck for the total distance, [tex]v_{average}[/tex] ≈ 53 km/h
The correct option is (d) 53 km
4. The heat, 'H', developed by the electric iron is given by the following formula;
H = I²·R·t
Where;
I = The current flowing in the electric iron = 5 A
R = The resistance of the iron = 20Ω
t = The time duration of the flow of the current = 30 s
∴ H = (5 A)² × 20 Ω × 30 s = 15,000 joules
The heat, developed by the electric iron, H = 15,000 joules
5. Let 'R' represent the resistance between A and B in each network
a) For the first network, we have;
1/R = 1/(2 + 2) + 1/(2 + 2) = 1/4 + 1/4 = 1/2
∴ R = 2 Ω
∴ The resistance between A and B is 2 Ω
b) For the second network, we have;
R = 1/(1/2 + 1/2) + 3 = 4
R = 4Ω
∴ The resistance between A and B is 4 Ω
c) For the third network, we have;
R = 2 + 1/(1/4 + 1/4) + 2 = 6
R = 6Ω
∴ The resistance between A and B is 6 Ω
d) For the fourth network, we have;
R = 1/(1/2 + 1/2) + 1/(1/2 + 1/2) = 2
R = 2Ω
∴ The resistance between A and B is 2 Ω
Related Questions
Explain why the "X" chromosome expresses more traits than the "y" chromosome.
Please answer :( I have a lot of homework to do today! If it’s good I’ll mark b. Links or st————-upidity will get reported! Please help:3
Answers
Explanation:
The X chromosome (females have 2 of them while males have 1) is five times larger than the Y chromosome and has 10 times the number of genes.
How can I rewrite the equation a - b = d using addition?
Answers
Explanation:
A=b+d that is the way to rewrite the equation
A 1.70 m long string has a standing wave with 2 loops at a frequency of 38.4 Hz. What is the speed of the waves in the string? (Unit = m/s)
Answers
Answer:65.28
Explanation:
A long string has a standing wave with 2 loops at a frequency. The speed of the waves in the string is 65.28 m/s
What is frequency?The frequency is the number of cycles completed per second.
Given the length of the string l = is 1.70 m, no of loops n =2, frequency of wave f =38.4 Hz, then the speed of the waves is
f = nv /2l
Substitute the following values, we get
v = 38.4 x 2 x 1.70 / 2
v =65.28 m/s
Thus, the speed of the waves in the string is 65.28 m/s.
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A team of scientists wants to conduct a study on an endangered animal inthe wild. Which rule should the study follow in order to be considered ethical?
A. The scientists will promote the study on their personal websites.
B. The animals will not be harmed during the study.
C. The study will gather data over a long period of time.
D. The study will answer a question that has never been investigated.
Answers
Answer:
imma have to say C I'm not sure tho
The Doppler Effect is caused by which of the following?
Select all that apply…
A - motion of the source
B - the type of wave
C - original frequency of the source
D - motion of the observer
E - type of medium the wave is in
Answers
Answer:
the type of wave
Explanation:
Description: Doppler Effect works on both light and sound objects. For instance, when a sound object moves towards you, the frequency of the sound waves increases, leading to a higher pitch. Conversely, if it moves away from you, the frequency of the sound waves decreases and the pitch comes down.
What type of circuit is pictured?
O Parallel Circuit
Series Circuit
Answers
Answer:
Parallel Circuit
Explanation:
Check the image below
in series circuits currents can only flow in one direction
In parallel circuits currents can flow through more than one path
Because the circuit shown has two pathways it is considered a parallel circuit
Answer:
Parallel Circuit
Explanation:
Hope this helps
How can seismographs be used to predict hurricane intensity?
Answers
Answer: The earth is a noisy place. Seismometers, which measure ground movements to detect earthquakes, volcanic eruptions, and manmade explosives, are constantly recording smaller vibrations caused by ocean waves, rushing rivers, and industrial activity.
Explanation:
Help!!! If you cannot type in the box, dont answer.
Answers
Exp: because I just can
Answer: lollllllllllllllllllllll
Explanation:
What is the wavelength of a wave that is traveling at 343 m/s with a frequency of 1000 Hz
Answers
Answer:
[tex]343 \div 1000 = 0.343[/tex]
wavelength is equivalent to the velocity divided by the frequency
Is telekinesis real??? I really wanna start learning it!
Answers
Answer:
if you only have to control your chakra and know how to get all your vibes to pass it to objects and it takes time to practice
Four round objects of equal mass and radius roll without slipping along a horizontal surface that then bends upward and backward into an arc of half a circle. The objects all have the same linear speed initially. The objects are a hollow cylinder, a solid cylinder, a solid sphere, and a hollow sphere. The objects to go up the arc and exit the are going in the opposite direction they entered without falling off the arc. Now, several trials are run for each object. For each trial, the initial speed of the object is reduced until the object does not make it through the full arc. The speed needed for each object to just make it through the arc is recorded. Which of the following correctly lists the objects in order from fastest to slowest speed needed to make it through the arc?
A. Hollow cylinder, hollow sphere, solid cylinder, solid sphere
B. Hollow cylinder, solid sphere, solid cylinder, hollow sphere
C. Solid sphere, solid cylinder, hollow sphere, hollow cylinder
D. Solid sphere, hollow sphere, solid cylinder, hollow cylinder
E. Hollow sphere, solid cylinder, hollow cylinder, solid sphere
Answers
Answer:
A
Explanation:
inertia Equation for All Object is k m R²
inertia Equation of Hollow Cylinder I = m R²
inertia Equation of Solid Cylinder I = ½ m R²
inertia Equation of Hollow Sphere I = ⅔ m R²
inertia Equation of Solid Sphere I = 2/5 m R²
to find the speed needed we can use Mechanical Energy (ME). or Total Energy.
ME = Translation Kinetic Energy + Rotation Kinetic Energi
ME = ½ m v² + ½ I w²
ME = ½ m v² (1 + k)
v² = 2ME / m(1+k)
sinnce all objects have the same mass, we can figure that v² is proportionally with 1/(1+k)
v²(hc) = 1/(1+1) = ½ = 0.5
v = 0.707
v²(sc) = 1/(1+½) = 2/3 = 0.67
v = 0.818
v²(hs) = 1/(1+⅔) = 3/5 = 0.6
v = 0.744
v²(ss) = 1/(1+²/5) = 5/7 = 0.71
v = 0.842
these is the ratio of speed they produce in the end of the arc with initial speed = 0 m/s
so, if we must give speed to the object so that it can reach the end of the arc, the fastest speed is given to hollow cylinder and the slowest speed is given to Solid Sphere
Then the answer is
HC, HS, SC, SS
Solid sphere, solid cylinder, hollow sphere, hollow cylinder correctly lists the objects in order from fastest to slowest speed needed to make it through the arc.
What is inertia?A body's inertia is a characteristic that makes it resist attempts to move it or, if it is already moving, to change the speed or direction of it.
Mathematically:
inertia All Object is = k m R²
inertia of Hollow Cylinder I₁ = m R²
inertia of Solid Cylinder I₂ = ½ m R²
inertia of Hollow Sphere I₃ = ⅔ m R²
inertia of Solid Sphere I₄ = 2/5 m R²
Total kinetic energy of a body while it roll without slipping = Translation Kinetic Energy + Rotation Kinetic Energi
= ½ m v² + ½ I w²
= ½ m v² (1 + k)
= 2 KE / m(1+k)
Since all objects have the same mass and, v² can be expressed as proportionally with 1/(1+k).
For hollow cylinder: v₁² = 1/(1+1) = ½ = 0.5
v₁ = 0.707
For solid cylinder: v₂²= 1/(1+½) = 2/3 = 0.67
v₂ = 0.818
For hollow sphere: v₃² = 1/(1+⅔) = 3/5 = 0.6
v₃ = 0.744
For solid sphere: v₄² = 1/(1+²/5) = 5/7 = 0.71
v ₄= 0.842
The objects in order from fastest to slowest speed needed to make it through the arc are correctly listed as:
solid sphere > solid cylinder > hollow sphere > hollow cylinder.
Option (C) is correct.
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1.Which of the following is the best example of motion?A.Waving your armsB.Tossing and turning in your bedC.Walking from home to schoolD.Your dog wagging his tail
Answers
Answer:
A
Explanation:
What type of energy is thermal energy? A. Sound energy B. Chemical energy C. Kinetic energy D. Nuclear energy
Answers
Answer:
kinetic energy
Explanation:
A point source emits sound waves with a power output of 135 watts. What is the sound level (in dB) at a distance of 10 m
Answers
Answer:
The sound level of the point source at a distance of 10 meters is approximately 110.294 decibels.
Explanation:
First, we calculate the intensity ([tex]I[/tex]), in watts per square meter, by the Inverse-Square Law:
[tex]I= \frac{\dot W}{4\pi\cdot r^{2}}[/tex] (1)
Where:
[tex]\dot W[/tex] - Power, in watts.
[tex]r[/tex] - Radius, in meters.
And the sound intenity level ([tex]L[/tex]), in decibels, is expressed by:
[tex]L = 10\cdot \log_{10} \frac{I}{I_{o}}[/tex] (2)
Where [tex]I_{o}[/tex] is the reference sound intensity, in watts per square meter.
If we know that [tex]\dot W = 135\,W[/tex], [tex]r = 10\,m[/tex] and [tex]I_{o} = 10^{-12}\,\frac{W}{m^{2}}[/tex], then we find that sound level at a distance of 10 meters is:
[tex]I= \frac{\dot W}{4\pi\cdot r^{2}}[/tex]
[tex]I = 0.107\,\frac{W}{m^{2}}[/tex]
[tex]L = 10\cdot \log_{10} \frac{I}{I_{o}}[/tex]
[tex]L \approx 110.294\,dB[/tex]
The sound level of the point source at a distance of 10 meters is approximately 110.294 decibels.
1. Why is the equivalent resistance in a parallel circuit equal to the sum of the reciprocals of the individual resistances, whereas in a series circuit, the equivalent resistance is the sum of the individual resistances?
Answers
Answer: Kirchhoff first law: sum of currents coming in branch and leaving it are same.
Explanation: in parallel circuit current is divided between resistors.
In series circuit same current passes through all resistors.
What is the net force if you pull a cart to the right with 5N of
force and a friend pushes the left to the left with 5 N of force
Answers
Answer:
In this case the net force is zero.
According to Newton's third law of motion: For every action, there is an equal and opposite reaction. In this case the net force is zero.
Explanation:
Hope this helps!! :)
Which statement describes one way that nuclear fission differs from nuclear fusion?
A. Nuclear fission can be sustained only in the Sun and other stars.
B. Nuclear fission can occur spontaneously.
C. The temperature required for nuclear fission is more than 15 million degrees Celsius.
D. It is more difficult to start and control nuclear fission,
Answers
Answer:
it is B
Explanation:
B
Statement B describes one way that nuclear fission differs from nuclear fusion in that nuclear fission can occur spontaneously.
What is nuclear power?The utilization of nuclear reactions to generate energy is known as a nuclear power. Nuclear fission, nuclear decay, and nuclear fusion processes are all sources of nuclear energy.
Nuclear power facilities currently produce the great bulk of the electricity generated by nuclear fission of uranium and plutonium.
Statement B describes one difference between nuclear fission and nuclear fusion in that nuclear fission can occur spontaneously.
Hence,option B is correct.
To learn more about nuclear power refer to the link;
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The only major country that does not use the metric system
A.
France
B.
United States
C.
Russia
D.
England
Answers
A waiter walks a distance of 5m holding a tray of food that weighs 10N. How much work has the waiter done on the tray?
Answers
Answer:
0 joule of workdone
Explanation:
[tex] w = f \times d \times \cot( \beta ) [/tex]
force and the displacement are perpendicular to each other so cos(90⁰) =0
Definition: The energy transferred by a force to a moving object.
Answers
Answer:
Force applied
Explanation:
An object will remain at its state of rest unless a non zero for act on it
Name the part of the respiratory system which is shared with the digestive system. What is the common name of that part?
Answers
The oropharynx is a passageway that is shared between the respiratory and digestive systems.
Which of the waves has the smallest amplitude?
A. The blue wave
B. The orange wave
C. The green wave
D. The red wave
Answers
Answer:
I think its the Blue wave, im not sure so dont take my word for it.
Explanation:
Answer: it’s the green wave
Explanation: trust me bro
Give 1 real life example of a scenario that takes advantage of the inverse relationship between force and time when impulse is constant. Describe how it is an example of impulse and how force and time are involved.
Answers
Answer:
On real life example of a scenario that takes advantage of the inverse relationship between force and time when impulse is constant is when making a serve with a lawn tennis racket
How It is an example of impulse is that when a serve is made by moving the bat slowly, the lawn tennis player uses less force and the ball is in contact with the string for longer a period
When however, the lawn tennis player moves the racket faster, with the strings of the racket highly tensioned he uses more force and the ball also spends less time on the racket to produce the same momentum
Explanation:
The impulse of a force, ΔP is given by the following formula;
ΔP = F × Δt
Where ΔP is constant, we have;
F ∝ 1/Δt
Therefore, for the same impulse, when the force is increased, the time of contact is decreases and vice versa.
1. What do you mean by energy conservation?
Answers
Answer: Energy conservation is the decision and practice of using less energy. Turning off the light when you leave the room, unplugging appliances when they're not in use and walking instead of driving are all examples of energy conservation.
Explanation: I'm not very sure but hope this is right
can someone help me please? thank you
Answers
A uniform plank of mass 10kg and length 10m rests on two supports, A and B as shown. A boy of weight 500N stands at a distance of 2m from A. Find the reaction forces U¹ and U² at the supports A and B respectively
Answers
Answer:
U² = 142.86 N
U¹ = 357.14 N
Explanation:
Taking summation of the moment about point A, we get the following equilibrium equation: (taking clockwise direction as positive)
[tex]W(2\ m) - U^2(7\ m) = 0[/tex]
where,
W = weight of boy = 500 N
U² = reaction ay B = ?
Therefore,
[tex](500\ N)(2\ m)-(U^2)(7\ m)=0\\U^2=\frac{1000\ Nm}{7\ m}\\[/tex]
U² = 142.86 N
Now, taking summation of forces on the plank. Taking upward direction as positive, for equilibrium position:
[tex]W-U^1-U^2=0\\500\ N - 142.86\ N = U^1\\[/tex]
U¹ = 357.14 N
The acceleration due to gravity on the Moon's surface is known to be about one-sixth of the acceleration due to gravity on the Earth.
A rock falls under a gravitational force of 16.3 N on the moon.
Please help me figure out the mass of the rock.
Answers
Answer:
The mass of the rock is approximately 9.97 kg
Explanation:
From the question, we have;
The acceleration due to gravity on the Moon = (1/6) × The acceleration due to gravity on the Earth
The gravitational force under which a rock falls on the Moon = 16.3 N
The acceleration due to gravity on Earth, g ≈ 9.81 m/s²
Therefore, the acceleration due to gravity on the Moon, a = (1/6) × 9.81 m/s² ≈ 1.635 m/s²
The relationship between the force with which the rock falls and the acceleration of the motion resulting in the force is given by the following relationship;
F = m × a
Where;
F = The force = 16.3 N
m = The mass of the object acted on by the force = The mass of the rock
a = The acceleration of the motion of the object = 1.635 m/s²
From F = m × a, we have;
m = F/a
∴ m = 16.3 N/(1.635 m/s²) = 9.96941896 kg
The mass of the rock, m ≈ 9.97 kg.
state and explain the disadvantages of anomalous expansion of water
Answers
Answer:
я не знаю старайся изо всех сил
Explanation:
[tex]\huge{\mathbb{\tt { QUESTION↓}}}[/tex]
[tex]\color{green}{\tt State \: and \: explain \: the \: disadvantages}[/tex]
[tex]\color{green}{\tt { of \: anomalous \: expansion \: of \: water}}[/tex]
[tex]\huge{\mathbb{\tt {ANSWER↓}}}[/tex]
[tex]{\boxed{\boxed{\tt { DISADVANTAGES \: of \: anomolous \: expansion \: of \: water }}}}[/tex]
Since the maximum density can be found for a positive temperature, water's own weight will prevent it from freezing from the bottom up. However, the anomalous expansion of water has some negative consequences. ... As the water freezes it expands and can rip pipes open.[tex]{\boxed{\boxed{\tt { What \: is \: the \: state \: of \: anomalous \: expansion \: of \: water? }}}}[/tex]
The anomalous expansion of water is an abnormal property of water whereby it expands instead of contracting when the temperature goes from 4o C to 0o C, and it becomes less dense. The density is maximum at 4 degree centigrade and decreases below that temperature as shown in graph#CarryOnLearning
#JustEnjoyTheSummer
→XxKim02xXIf you want brainiest, can you help me?
Answers
Answer
?????
Explanation:
How does the mass of a satellite, moon or asteroid affect its orbital speed?