describe the difference between mechanical and electromagnetic waves. Give an example of each kind of wave related to telecommunications.
A 60-kg skier starts from rest from the top of a 50-m high slope. if the work done by friction is -6.0 kj, what is the speed of the skier on reaching the bottom of the slope?
Answer:
27.9 m/s
Explanation:
You want the speed of a 60 kg skier at the bottom of a 50 m high slope if 6 kJ of energy is lost to friction.
Potential energyThe potential energy of the skier at the top of the slope is ...
PE = mgh
PE = (60 kg)(9.8 m/s²)(50 m)
Kinetic energyThe kinetic energy of the skier at the bottom of the slope is this potential energy, less the energy lost due to friction.
KE = PE -6000 J
That is related to the skier's speed by ...
KE = 1/2mv²
So, the speed is ...
[tex]v^2=\dfrac{2\cdot KE}{m}=\dfrac{2(mgh-6000)}{m}=2\left(gh-\dfrac{6000}{m}\right)\\\\\\v^2=2\left(9.8\cdot50-\dfrac{6000}{60}\right)=780\\\\\\v=\sqrt{780}\approx27.9\quad\text{m/s}[/tex]
The speed of the skier at the bottom of the slope is about 27.9 m/s.
What is the main reason why many nuclear power plants are located near bodies of water?
Estimate the first three standing-wave frequencies of the vocal tract. use v=344m/s. (the answers are only an estimate, since the position of lips and tongue affects the motion of air in the vocal tract.)
A torque applied to a flywheel causes it to accelerate uniformly from a speed of 161 rev/min to a speed of 853 rev/min in 5.0 seconds. determine the number of revolutions n through which the wheel turns during this interval. (suggestion: use revolutions and minutes for units in your calculations.)
Rocket engineers use newton's third law during launch. identify the action force.
A. exhaust gases push down on the earth
B. rocket travels upward
C. earth pushes back on the exhaust gases
The action force in this scenario is earth pushes back on the exhaust gases.
Explanation:The action force in this scenario is option C: earth pushes back on the exhaust gases.
Newton's third law states that for every action, there is an equal and opposite reaction. In this case, the action force is the exhaust gases pushing downward on the earth as the rocket launches. The reaction force is the earth pushing back on the exhaust gases with an equal force in the opposite direction.
So, while the rocket is traveling upward, the action force is the exhaust gases pushing downward on the earth and the reaction force is the earth pushing back on the exhaust gases.
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Which graphic design tools help you draw circles and rectangles?
Freehand tool
Geometric Shape tools
Vector Splines
Drawing tool
Geometric shape tools help you draw circles and rectangles. Option B is correct.
What is graphic design?Graphic design is the practice of using words, pictures, and other visual elements to communicate ideas to an audience, often in order to achieve a certain result.
In other words, graphic design serves as a tool for communicating ideas through imagery and design.
For those with imaginative thinking skills who appreciate art, technology, and communication, graphic design is a terrific job.
Every business has a need for design, therefore graphic designers have a lot of opportunities to work on a variety of brand-new, fascinating projects.
You can draw circles and rectangles using geometric form tools.
Hence, option B is correct.
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Which statements describe chemical changes? Check all that apply.
The after-rain smell is produced by an interaction between rain and the oils released by plants.
A homemade volcano can be created by combining baking soda and vinegar. When it erupts, carbon dioxide gas is released.
Sheep are sheared for their wool. The wool is cleaned and twisted into yarn. The yarn is dyed and used to knit clothing.
The Statue of Liberty has turned green over time due to the reaction of copper with carbon dioxide and water.
Mosaic art is created by smashing colored glass tiles and rearranging them to form a picture or design.
The answers are a,b and d
Answer: A, B, and D
A lunar exploration vehicle was created by a research team. It weighs 3,000 kg on the earth. It needs an acceleration of 10 m/s2 on the moon. In order to have the same acceleration, what will be the net force acting on the vehicle on the earth?
A two-phase, liquid–vapor mixture of h2o, initially at x 5 30% and a pressure of 100 kpa, is contained in a piston– cylinder assembly, as shown in fig p3.77. the mass of the piston is 10 kg, and its diameter is 15 cm. the pressure of the surroundings is 100 kpa. as the water is heated, the pressure inside the cylinder remains constant until the piston hits the stops. heat transfer to the water continues at constant volume until the pressure is 150 kpa. friction between the piston and the cylinder wall and kinetic and potential energy effects are negligible. for the overall process of the water, determine the work and heat transfer, each in kj.
Final answer:
In this scenario, the work done by the external agent can be calculated using the change in volume, and no heat is exchanged during this process.
Explanation:
Work: In the given scenario, since the gas volume doubles at constant temperature, the work done by the external agent can be calculated using the formula W = -PΔV, where P is the pressure and ΔV is the change in volume.
Heat Transfer: As the gas volume doubles at constant temperature, no heat is exchanged during this process. Hence, the heat exchanged is zero.
The national grid supplied a house with 18000000 J of energy in 1 hour. What was the average current supplied to the house in that hour? Write any equations that you use.
The average current supplied to the house in one hour can be found by dividing the energy supplied by the voltage. In this case, the average current is 5 Amperes.
Explanation:To find the average current supplied to the house, we can use the equation: I = Q / t, where I is the current, Q is the charge, and t is the time. In this case, the energy supplied is 18,000,000 J, so we can find the charge using the equation: Q = E / V, where E is the energy and V is the voltage. Given that the time is 1 hour, we can calculate the average current using the equation: I = Q / t.
First, we need to convert the energy from joules to kilowatt-hours: 1 kWh = 3,600,000 J. So, the energy supplied to the house is 5 kWh.
The average current can now be calculated as follows: I = E / V = 5 kWh / 1 hour = 5 A. Therefore, the average current supplied to the house in that hour is 5 Amperes.
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What does 34.9cL equal in hL
You are riding your bike to the mall. You travel the first mile in 10 minutes. The last mile takes you 15 minutes. This is an example of
Answer:
negative exccalarion
Explanation:
what was perphaps the greatest challenge of human space flight?
A satellite of mass 6500 kg orbits the earth in a circular orbit of radius of 7.5 106 m (this is above the earth's atmosphere).the mass of the earth is 6.0 1024 kg. what is the speed of the satellite?
The two forces, centripetal force and gravity are
equal
So, G M m / r^2 = (m V^2) / r
so sqrt (GM/r)= V
G is a gravitational constant which is G=6,67.10exp(-11)
Sqrt (6.67 x 10^-11) (6 x 10^24)/7.5 x 10^6
so V= 7.30479295e9 or 7305 m/s
Final answer:
To find the speed of a satellite in Earth orbit, we use the formula for orbital speed with the Earth's mass and the orbit's radius. After calculation, the satellite's speed is found to be approximately 7357.7 m/s.
Explanation:
The question asks for the speed of a satellite of mass 6500 kg orbiting the Earth in a circular orbit with a radius of 7.5 × 106 m. The mass of the Earth is given as 6.0 × 1024 kg. To find the speed of the satellite, we use the formula for the orbital speed:
v = √(GM/r)
where v is the orbital speed, G is the gravitational constant (6.674 × 10−12 Nm2/kg2), M is the mass of the Earth, and r is the radius of the orbit. Plugging in the given values:
v = √((6.674 × 10−12 × 6.0 × 1024) / 7.5 × 106)
After performing the calculation, we find that the speed of the satellite is approximately 7357.7 m/s.
if you conduct an expiriment that uses lots of paper and plastic how can you practice good science ethics ?
Which word equation is used to calculate the acceleration of an object? A. Subtract the initial velocity from the final velocity and multiply the result by the time. B. Subtract the initial velocity from the final velocity and divide the result by the time. C. Add the initial velocity and the final velocity and divide the result by the time. D. Add the initial velocity and the final velocity and multiply the result by the time.
Final answer:
The correct word equation to calculate the acceleration of an object is to subtract the initial velocity from the final velocity and then divide the result by the time.
Explanation:
To calculate the acceleration of an object, you would use the following word equation: Subtract the initial velocity from the final velocity and divide the result by the time. This represents the average acceleration, where acceleration is defined as the change in velocity (∆v) divided by the change in time (∆t).
It is crucial to ensure that all units are consistent, typically using meters for distance and seconds for time. An example of calculating acceleration would be: If an object's initial velocity is 5 m/s, its final velocity is 20 m/s, and the time taken to change velocity is 3 seconds, the acceleration a is (20 - 5) / 3 = 15 / 3 = 5 .
Using Figure 25-2, determine how Giant stars differ from main sequence stars.
Answer:
Giant stars differ from main sequence stars in having greater absolute magnitudes for the same temperatures.
A circular loop of wire with a radius of 4.0 cm is in a uniform magnetic field of magnitude 0.069 t. the plane of the loop is perpendicular to the direction of the magnetic field. in a time interval of 0.46 s, the magnetic field changes to the opposite direction with a magnitude of 0.044 t. what is the magnitude of the average emf induced in the loop?
The standard unit of work in the metric system is named after the scientist _____. 1 Albert Einstein 2 James Joule 3 Isaac Newton 4 James Watt
A volleyball is dropped from a cliff and a soccer ball is thrown upward from the same position. When each ball reaches the ground at the bottom of the cliff, the volleyball will hit the ground with greater velocity.
The second law of thermodynamics dictates that ____. 1 point low-quality energy becomes static some high-quality energy is always degraded the amount of energy in the universe is constantly changing low-quality energy is required to get high-quality energy
Final answer:
The second law of thermodynamics states that in any energy transfer, some high-quality energy is always degraded, leading to increased disorder or entropy in the system.
Explanation:
The second law of thermodynamics dictates that some high-quality energy is always degraded to a lower quality form during energy transfers. This law further implies that no energy transfer is completely efficient, thus resulting in an increase in entropy, or disorder, within a system. This is a fundamental concept in physics that puts an arrow on the transformations of matter and energy, signifying a one-way flow from usable to less-usable forms of energy. It is most commonly observed through heat loss, where energy spontaneously transfers from a hotter object to a cooler one, increasing the disorder of the system.
Suppose we are told that the acceleration a of a particle moving with uniform speed v in a circle of radius r is proportional to some power of r, say rn, and some power of v, say vm. Determine the values of n and m and write the simplest form of an equation for the acceleration.
Answer:
Acceleration, [tex]a=k\dfrac{v^2}{r}[/tex]
Explanation:
It is given that, the acceleration a of a particle moving with uniform speed v in a circle of radius r is proportional to some power of r and some power of v. Mathematically, it can be written as :
[tex]a\propto r^nv^m[/tex]
or
[tex]a=r^nv^m[/tex]...........(1)
Dimensional formula of a = [tex][LT^{-2}][/tex]
Dimensional formula of r = [tex][L][/tex]
Dimensional formula of v = [tex][LT^{-1}][/tex]
Using dimensional analysis in equation (1) as :
[tex][LT^{-2}]=[L]^n[LT^{-1}]^m[/tex]
[tex][LT^{-2}]=[L]^{n+m}[T^{-m}][/tex]
Equation both sides of equation as :
n + m = 1, m = 2
This gives, n = -1
Use the value of m and n in equation (1) in order to get the formula :
[tex]a=kr^{-1}v^2[/tex]
[tex]a=k\dfrac{v^2}{r}[/tex]
Hence, this is the required solution.
the applied force required to push something across a surface as friction increases is what?
The current in a hair dryer measures 15 amps. The resistance of the hair dryer is 14 ohms. What is the voltage?
i'm pretty terrible at math, if you could explain how to found the correct answer to help future problems i would greatly appreciate it!
A diver who is 10.0 meters underwater experience has a pressure of 202 kPa. If the diver’s surface area is 1.50 meters squared, with how much total force does the water push on the diver?
To determine the total force exerted on the diver, multiply the pressure (in pascals) by the surface area. The total force is 303,000 newtons.
Explanation:To calculate the total force exerted by the water on a diver who is 10.0 meters underwater, we need to apply the concept of pressure which is defined as force per unit area. Given the pressure experienced by the diver is 202 kPa and the diver's surface area is 1.50 meters squared, we can use the formula Force = Pressure × Area.
First, we need to convert the pressure from kilopascals to pascals since one kilopascal equals 1,000 pascals:
202 kPa × 1,000 = 202,000 Pa
Then, we multiply the pressure by the diver's surface area to find the total force:
Total Force = 202,000 Pa × 1.50 m² = 303,000 N
Therefore, the water pushes on the diver with a total force of 303,000 newtons.
Calculate the average translational kinetic energy (sometimes just called average kinetic energy)⦠for one mole of gas at 827 k. and... for a single gas molecule at 827 k.
The average translational kinetic energy, or thermal energy, of a molecule can be found using the equation KE = 3/2kT. For one mole of gas at 827K, you multiply the single particle kinetic energy by Avogadro's number. For a single gas molecule at 827K, add its temperature into the equation to find its kinetic energy.
Explanation:The average translational kinetic energy of a molecule, also known as thermal energy, can be calculated using the equation KE = 3/2kT, where 'k' is the Boltzmann's constant (1.38 x 10^-23 J/K), 'T' is the absolute temperature in Kelvin, and KE is the average kinetic energy.
Now to calculate for one mole of gas at 827 K, multiply the single particle kinetic energy by Avogadro's number since one mole consists of Avogadro's number of particles. Hence, KE of one mole= NA * KE of one particle = 6.022 x 10^23 * KE of one particle. This answers the first part of your question.
In the case of a single gas molecule, using the temperature of 827 K, substitute this into the equation KE = 3/2kT to find the kinetic energy for an individual molecule. Remember the unit for your answer is Joules. This addresses the second part of your question.
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the potential energy of an apple is 6.00 joules. the apple is 3.00 meters high. what is the mass of the apple?
By rearranging the formula for gravitational potential energy, we calculate that the mass of the apple is approximately 0.2041 kg when its potential energy is 6.00 joules at a height of 3.00 meters.
To calculate the mass of the apple using its potential energy (PE) and the height (h) at which it is located, we use the formula for gravitational potential energy:
PE = mgh
where:
m is the mass in kilograms,g is the acceleration due to gravity (9.8 m/s² on Earth), andh is the height in meters.Given that PE = 6.00 Joules and h = 3.00 meters, we rearrange the formula to solve for m:
m = PE / (gh)
Substituting in the known values:
m = 6.00 J / (9.8 m/s² * 3.00 m) = 0.2041 kg
Therefore, the mass of the apple is approximately 0.2041 kg.
A transformer changes the 10,000 v power line to 120 v. if the primary coil contains 750 turns, how many turns are on the secondary?
a rectangular garden has a perimeter of 54 feet. it's length is 3 less than twice its width. write and solve an equation to solve for the gardens dimensions