Answer:
See below
Explanation:
rho = R A/l R = resistance A = cross sectional area l = length
A 49.0 kg child sits on the top of a slide that is located 1.80 m above the ground. After her descent, the child reaches a velocity of 3.00 m/s at the bottom of the slide. Calculate how efficiently the potential energy is converted to kinetic energy. Round to the nearest tenth.
For the potential energy is converted to kinetic energy is mathematically given as
n=24.44%
What efficiency of the potential energy is converted to kinetic energy?
Generally, the equation for the potential energy is mathematically given as
Ei=mgh
Ei=49.0\*9.81* 1.8
Ei=865.24J
Final total energy
K.E=0.5mv^2
K.E=0.5*49.0* (3.00)^2
K.E=211.5J
In conclusion, efficiency
n=Ef/Ei*100
n=211.5*865.24*100
n=24.44%
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what is kinematics ?
explain ~
Kinematics is the branch of physics and a subdivision of classical mechanics concerned with the geometrically possible motion of a body or system of bodies without consideration of the forces involved. :)
Answer:
Kinematics is a branch of mechanics that deals with pure motion, without reference to the masses or forces involved in it.
Explanation:
Ex. X=2t+1 here x is related to t which is time(function of time)
Which of the following was NOT one of Ghana's chief trading exports?
A. Gold
B. Ivory
C. Horses
Answer:
ivory. ..................
_______is the resistance to motion offered by an object sliding over a surface
friction is the force that resists the sliding or rolling of an object over another.
Black holes:
A are the brightest objects in space.
B are the most well understood objects in space.
C pulse in a regular pattern.
D None of the choices are correct.
Answer:
Black holes:
A are the brightest objects in space.
B are the most well understood objects in space.
C pulse in a regular pattern.
D None of the choices are correct.
Explanation:
A black hole is a region of space where the pull of gravity is so strong that nothing can escape. It's a "hole" in the sense that things can fall in, but not out of it. It is "black" in the sense that not even light can escape.
I hope I helped you! :)
Which term is defined as the change in the direction of light when it goes from one medium into a different medium?
Question 7 options:
Reflection
Refraction
Transmission
Absorption
Answer:
refraction
Explanation:
The following graph shows the force exerted on and the displacement of object being pulled
Find the work done to pull the object 7.0 m
The work done to pull the object 7.0 m is the total area under the graph from 0.0 m to 7.0 m, determined as 245 J.
Work done by the applied forceThe area under force versus displacement graph is work done.
The total work done by pulling the object 7 m, can be grouped into two areas;
First area, A1 = area of triangle from 0 m to 2.0 mSecond area, A2 = area of trapezium, from 2.0 m to 7.0 mA1 = ¹/₂ bh
A1 = ¹/₂ x (2) x (20)
A1 = 20 J
A2 = ¹/₂(large base + small base) x height
A2 = ¹/₂[(7 - 2) + (7-3)] x 50
A2 = ¹/₂(5 + 4) x 50
A2 = 225 J
Total work doneW = A1 + A2
W = 20 J + 225 J
W = 245 J
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Questions:
What are Newton’s Three Laws of Motion?
Explain what you learned about how the planets orbit around the Sun (Kepler’s Laws).
What are the Fundamental Forces?
Give some examples of the force vectors shown in force diagrams.
What is the normal force and what direction does the force arrow point on the force diagram?
What is the name of the force that is a combination of all forces that act on an object?
If you go to the Moon, explain what happens to your mass and weight.
Define mass and weight.
Does an object at rest have forces acting on it?
What is Inertia? What does it apply to?
You are pushing a book across a desk with a constant velocity. What are the forces acting on the book and in what direction? Are the y-forces equal in magnitude, why or why not? Are the x-forces equal in magnitude, why or why not? Explain using Newton’s Second Law. If you push on the book, according to Newton’s Third Law of Motion, what is the equal and reactive force?
The planets orbit the sun due to gravitational force of the sun on them which keep it in their orbits.
The Newton's three laws of motion are the following:The first law of motion is also called Law of Inertia, the second law of motion is the Law of Mass and Acceleration, and the Third Law of Motion that have action and reaction forces.
How the planets orbit around the Sun?The gravity of the Sun keeps the planets in their orbits. They stay and revolve in their orbits because there is no other force in the Solar System which can put pressure on them.
So we can conclude that planets orbit the sun due to gravitational force of the sun on them which keep it in their orbits.
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A sample from a meteorite that landed on Earth has been analyzed, and the result shows that out of every 1,000 nuclei of potassium-40 originally in the meteorite, only 250 are still present, meaning they have not yet decayed. How old is the meteorite (in yr)?
If the slump and subsequent flow continue migrating uphill and more material flows downhill, which of the following are a hazard? (select all that apply)
A. The homes will be damaged.
B. The roadway will be damaged.
C. Utility power poles will be damaged.
D. More agricultural land will be unfarmable.
The hazard from more material flows downhill are:
The roadway will be damaged.More agricultural land will be unfarmable.Utility power poles will be damagedWhat is Hazard?This is a condition which has the potential to cause damage or injury to a person or property.
Materials flowing downward means that there will erosion which may damage the roads, land for agriculture and utility poles.
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A particle has a velocity that is 70 % of the speed of light and weighs 206.8 times the mass of an electron. Find the wavelength of this particle?
For a particle that has a velocity that is 70 % of the speed of light and weighs 206.8 times the mass of an electron, the wavelength of this particle is mathematically given as
W= 739.47
What is the wavelength of this particle?Generally, the equation for the 70 % of the speed of light is mathematically given as
70% of 3x10^8 = 2.1x10^8 m/s
Therefore
206.8*9.11x10^-31 = 1.88x10^-28 kg
In conclusion, The wavelength equation isTThe
wavelength= plancks constant / (mass*velocity)
Where
Plancks constant = 6.62x10^-34 m^2 kg/s
W=6.62x10^-34 / (1.88x10^-28/2.1x10^8)
W= 739.47
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What is the index of refraction of a liquid if the angle of incidence in air is 35 degrees and the angle of refraction is 14 degrees?
After a boater runs out of gas a boater considers dropping the motor into the water to create waves describe the resuming motion of the boat and explains why the boaters plan will not help him reach shore ????
The boat will swing back and forth about the same location, never reaching the land. Due to which the boaters plan will not help him reach shore.
Describe boat motion?The ship rocks back and forth as the wind and waves press against it. Similar to swiveling on a chair, yaw spins the ship on an unseen central line.
Waves travelling perpendicular to the ship's motion might create this, changing the ship's heading or direction.
The motion of the motor will be identical to that of water molecules. Because there is a wave on the water surface,The motor will move in lockstep with the water particle.
The particles of the medium only vibrate perpendicular to the wave propagation as the wave travels through the water surface, but they are not moved from their initial position.
As a result, the boat will swing back and forth about the same location, never reaching the land.
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How do you find the range of a data set?
Answer: You take the biggest number and subtract it from the smallest number.
Explanation: Hope this helps.
Answer:
Subtract the minimum data value from the maximum data value to find the data range.
Explanation:
[tex]Hope[/tex] [tex]this[/tex] [tex]helps![/tex]
Select the star life cycle that is accurate.
A. Nebula, star of two stellar mass, supernova, black hole
B. Star of three stellar masses, red supergiant, supernova, neutron
star
C. Supernova, star of three stellar masses, black hole, nebula
D. Nebula, white dwarf, red giant, black hole
Answer:
B according to the picture
Explanation:
Star of 3 stellar masses => red supergiant=>supernova=>neutron star
Star of three stellar masses, red supergiant, supernova, neutron star are the star life cycle that is accurate. Therefore, the correct option is option B.
A star's life cycle is as follows: star formation inside a nebula, evolution into a sequence star, sustained nuclear fusion for a long time, exhaustion of fuel at some point, and gravitational core collapse with resulting high pressures and temperatures.
They typically consist of heated plasma held together by a strong gravitational force and are self-luminous. The thermonuclear process between helium and hydrogen that takes place in a star's core causes it to glow brilliantly. Star of three stellar masses, red supergiant, supernova, neutron star are the star life cycle that is accurate.
Therefore, the correct option is option B.
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Q5- Knowing now that your mood might affect your memory, what strategies could you employ to assist your memories and make sure that you forget less information when you are having a good time?
An object has a momentum of 4,000 kg-m/s and a mass of 115 kg. It crashes into another object that has a mass of 100 kg, and the two objects stick together. If the momentum is conserved, what is the new velocity of the combined object? Round to the nearest hundredth.
Answer:
18.60 m/s
Explanation:
Original momentum = mv = 4000 with m = 115
after collision m = 115 + 100 = 215 kg
but the total momentum is still the same (conserved)
4000 = 215 v shows v = 18.60 m/s
Answer:
18.60
Explanation:
CPR combines which two processes to keep a person alive until medical personnel arrive?
A. Rescue breathing and chest compressions
B. Chest compressions and RICE
C. Rescue breathing and AED
Your answer will be A. Rescue breathing and chest compressions.
Electromagnetic waves(such as light, gamma rays, microwaves, etc.) exhibit a longitudinal wave form.
True
False
Answer:
False - Electromagnetic waves are transverse waves - they do not need a particular medium for transmission - as sound waves in air (longitudinal waves)
The magnetic flux through a coil of wire containing two loops changes from -65 Wb to +47 Wb in 0.38 s What is the emf induced in the coil? Express your answer using two significant figures
Hi there!
Recall Faraday's Law:
[tex]\epsilon = N\frac{d\Phi_B}{dt}[/tex]
ε = Induced emf (V)
N = Number of Loops
φ = Magnetic Flux (Wb)
t = time (s)
Thus, the induced emf is equivalent to the number of loops of the coil times the rate of change of the magnetic flux bounded by the area of the coil, so:
[tex]\epsilon = 2 \cdot \frac{47 - (-65)}{0.38} = 2 \cdot \frac{112}{0.38} = 589.47V =\boxed{ 5.9 \times 10^2 V}}[/tex]
**This is the magnitude of the induced emf. With Lenz's Law, however, the answer would be negative, which just indicates it is a resistive emf.
I have to make a presentation about ultrasound diagnostic (it's for physics). Does someone know more about that topic? I need to explain how does ultrasound show insides of human body.
*sorry if my english isn't that good, im from Cro
Answer: Okay so I don't know much but from what I do know
Ultrasound emits sound waves into the body and what bounces back is what they can see the grey shape is what is closest. It's all micro sound waves and cannot hurt an unborn baby.
Explanation:
Not sure if this is correct but it is what I remember being told.
Hope this helps!
Some electronic devices operate on a DC voltage of 7.5 V. To obtain 7.5 V DC from a 120-V (rms) AC line, first the voltage is dropped to 7.5 V (rms) AC by a transformer, and then the 7.5 V AC is converted to 7.5 V DC by a rectifier circuit involving diodes. Consider a device of resistance 15 Ω connected to the 7.5-V DC output of the rectifier. Assuming no power loss anywhere, what is the rms current, in amperes, in the secondary winding? Again assuming no power loss anywhere, what is the rms current, in milliamperes, in the primary winding?
The rms current, in amperes, in the secondary winding is 0.5 A and the rms current, in milliamperes, in the primary winding is 31.25 mA.
Output current
The rms current, in amperes, in the secondary winding is calculated as follows;
V = IR
I = V/R
I = 7.5 / 15
I = 0.5 A
Input currentThe rms current, in milliamperes, in the primary winding is calculated as follows;
[tex]\frac{I_p}{I_s} = \frac{V_s}{V_p} \\\\I_p = \frac{V_sI_s}{V_p}\\\\I_p = \frac{7.5 \times 0.5}{120} \\\\I_p = 0.03125\\\\I_p = 31.25 \ mA[/tex]
Thus, the rms current, in amperes, in the secondary winding is 0.5 A and the rms current, in milliamperes, in the primary winding is 31.25 mA.
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27. What do we mean when we say that a simple machine uses mechanical advantage to
make a "tradeoff" between force and distance?
Answer:
Work = Force * Distance definition of work
W = F * d
If one uses 1/2 the force to move an object, then he must move the force thru twice the distance to get the same work output.
Which is an example of radiation?
Answer:
A burning candle emits radiation in the form of heat and light. The Sun emits radiation in the form of light, heat, and particles. Uranium-238 decaying into Thorium-234 emits radiation in the form ofalpha particles.
Answer:
the sun
Explanation:
the sun emits radiation
Show instructions
Question 5 (8 points)
Which is an example of kinetic friction?
friction between a car's wheels and the road as the car moves
friction between your shoes and the ground when you stand still
friction between a sticky note and the page of a book as it marks your pla
O friction between your skin and a pencil as it rests in your palm
0 0
UD
Answer:
The car and the road have kinetic friction.
Explanation:
Because the car is getting a force of friction because of the kinetic energy caused by the engine.
How do landforms and rock layers support the plate tectonic theory
Why is simple machine important ?...
Answer: Simple Machines are useful and important because they reduce effort or extend the ability of people to form tasks beyond their normal capabilities . So they help us in our daily lives by reducing the amount of effort it takes for humans to perform certain tasks .
HOPE IT HELPS YOU .PLEASE GIVE BRAINLIEST .THANKS .
Convert 25 meters per second (m/s) to kilometers per hour (km/hr).
Оа
9.0 x 10^-2 km/hr
Oь
9.0 x 10^-1 km/hr
Ос
9.0 x 10^1 km/hr
Od
9.0 x 10^2 km/hr
Answer:
9 x 10^1 km/hr
Explanation:
25 m/s x 3600 sec / hr x 1km / 1000 m = 90 km/hr
An ideal engine (Carnot) is rated at 50 % efficiency when it is able to exhaust heat at a temperature of 20 ºC. If the exhaust temperature is lowered to 30 ºC, what is the new efficiency.
The new efficiency of the ideal engine rated at 50% is : 59%
Given data :
Inital exhaust temperature = 20ºC
Final exhaust temperature = - 30 ºC
The efficiency of an ideal engine can be calculated with the formula below
η = 1 - Texhaust / Tinput
Therefore :
Tinput = Texhaust / 1 - η ---- ( 2 )
where : Texhaust = 293 k , η = 0.50 ,
insert values into equation ( 2 )
Tinput = 293 / 1 - 0.50
= 586 k
Calculate the new efficiencyThe new efficiency of the ideal engine ;
η = 1 - T'exhaust / Tinput
= 1 - 243 / 586
= 1 - 0.41 = 59%
Hence we can conclude that the new efficieny is 59%
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Help with these questions
Answer:
sorry im not good at math so sorry i cant help
Explanation: