Answer:
The Greeks had drama and arts competitions that were considered very popular, and important in society.
Explanation:
hope it helps!
Some metals have a molecular structure that makes them good conductors. Explain how understanding this relationship can help engineers make more powerful batteries.
Answer:
Explained below.
Explanation:
Conductors can be defined as materials that permit electricity to flow through them easily.
Now, metals have a molecular structure that makes them good conductors because electrons in the atoms of these conductors tend to move freely from one atom to the other. So a majority of metals make good conductors because these metals tend to hold their electrons loosely. In short, it can help engineers make powerful batteries because then it means that they are capable of giving much more electrical energy since nowadays, advanced batteries make use of ion charges for the batteries.
A pail in a water well is hoisted by means of a frictionless winch, which consists of a spool and a hand crank. When Jill turns the winch at her fastest water-fetching rate, she can lift the pail the 28.0 m to the top in 11.0 s. Calculate the average power supplied by Jill's muscles during the upward ascent. Assume the pail of water when full has a mass of 7.30 kg.
Answer:
182.28 W
Explanation:
Here ,
m = 7.30 Kg
distance , d= 28.0 m
time , t = 11.0 s
average power supplied = change in potential energy/time
average power supplied = m×g×d/time
average power supplied = 7.30×9.81×28/11
average power supplied = 182.28 W
the average power supplied is 182.28 W
A little girl pushes a 5.0 kg toy baby stroller at constant speed 7.0 m across the floor. She pushes on the handle with a force of 40 N at an angle of 30o with the horizontal. All parts are 4 points each.
Complete Question
1 a A little girl pushes a 5.0 kg toy baby stroller at constant speed 7.0 m across the floor. She pushes on the handle with a force of 40 N at an angle of 30o with the horizontal. How much work is done by the girl on the wagon?
1b A farmhand pushes 20 ㎏ bale of hay 4m across the floor of the barn if she exerts a horizontal force of 60 N on the hay, how much work is done? (5 pts)
All parts are 4 points each
Answer:
1a
[tex]W = 242.5 \ J[/tex]
1b
[tex]W = 240 \ J[/tex]
Explanation:
Considering question a
From the question we are told that
The mass of the toy baby stroller is [tex]m = 5.0 \ kg[/tex]
The distance covered is [tex]d = 7.0\ m[/tex]
The force the girl applies on the handle is [tex]F = 40 \ N[/tex]
The angle at which this force is applied is [tex]\theta = 30^o[/tex]
Generally the workdone is mathematically represented as
[tex]W = F_x * d[/tex]
Here [tex]F_x[/tex] is the force along the horizontal axis , this is mathematically represented as
[tex]F_x = F cos (\theta )[/tex]
=> [tex]F_x = 40 * cos(30 )[/tex]
=> [tex]F_x = 34.64 \ N[/tex]
So
[tex]W = 34.64 * 7[/tex]
=> [tex]W = 242.5 \ J[/tex]
Considering question b
From the question we are told that
The mass of the toy baby stroller is [tex]m = 20 \ kg[/tex]
The distance covered is [tex]d = 4 \ m[/tex]
The force the girl applies on the handle is [tex]F = 60 \ N[/tex]
Generally the workdone is mathematically represented as
[tex]W = F * d[/tex]
=> [tex]W = 60 * 4[/tex]
=> [tex]W = 240 \ J[/tex]
a 2kg block is attached to a horizontal ideal spring with a spring constant of 200 Newton per minute. when the spring has its equillibrium length of block is given a speed of 5mps. what is the maximum elongation of the spring
Answer:
The maximum elongation of the spring is 0.5 meters.
Explanation:
The statement is incorrect. The correct form is:
A 2-kg block is attached to a horizontal ideal spring with a spring constant of 200 newton per meter. When the spring has its equillibrium length, the block has a speed of 5 meters per second. What is the maximum elongation of the spring?
The block experiments a simple harmonic motion, where there are no non-conservative forces and the total energy is the sum of translational kinetic energy of the mass and the elastic potential energy of the spring. The maximum elongation of the spring is done when elastic potential energy reach its maximum. By the Principle of Energy Conservation, the maximum elastic potential energy is equal to the maximum translational kinetic energy, which corresponds to the instant when the mass reaches the equilibrium position. Then, the equation modelling the system is:
[tex]U_{max} = K_{max}[/tex] (1)
Where:
[tex]U_{max}[/tex] - Maximum elastic potential energy of the spring, measured in joules.
[tex]K_{max}[/tex] - Maximum translational kinetic energy of the mass, measured in joules.
By definitions of the maximum elastic potential energy of the spring and the maximum translational kinetic energy of the mass, the expression above is expanded and simplified:
[tex]\frac{1}{2}\cdot k\cdot x_{max}^{2} = \frac{1}{2}\cdot m \cdot v_{max}^{2}[/tex]
[tex]x_{max} = \sqrt{\frac{m}{k} }\cdot v_{max}[/tex] (2)
Where:
[tex]x_{max}[/tex] - Maximum elongation of the spring, measured in meters.
[tex]m[/tex] - Mass, measured in kilograms.
[tex]k[/tex] - Spring constant, measured in newtons per meter.
[tex]v_{max}[/tex] - Maximum speed of the mass, measured in meters per second.
If we know that [tex]m = 2\,kg[/tex], [tex]k = 200\,\frac{N}{m}[/tex] and [tex]v_{max} = 5\,\frac{m}{s}[/tex], then the maximum elongation of the spring is:
[tex]x_{max} = \sqrt{\frac{2\,kg}{200\,\frac{N}{m} } }\cdot \left(5\,\frac{m}{s} \right)[/tex]
[tex]x_{max} = 0.5\,m[/tex]
The maximum elongation of the spring is 0.5 meters.
A particle starts from rest and moves with a constant acceleration. It travels the first 16 m in 4 s.
The time (in second) at which the velocity of the particle becomes. 8. m/s is:
a) 3
b) 4
c) 5
d) 6
e) 7
Answer:
B
Explanation:
10) The coil of transformer is coated by enamel why
Answer:
Enamel is used to coat the wires, it is the thinnest possible insulator. The coils are made up of large number of turns and enamel makes it possible to cram a lot of wires (coils) in much smaller space.
Mark all the units for speed
Answer:
Speed. I am speed.
Explanation:
The FitnessGram Pacer Test is a multistage aerobic capacity test that progressively gets more difficult as it continues. The 20 meter pacer test will begin in 30 seconds. Line up at the start. The running speed starts slowly, but gets faster each minute after you hear this signal. A single lap should be completed each time you hear this sound. Remember to run in a straight line, and run as long as possible.
Explain how polarization of a cell increases the cell's internal resistance.
(2
2.
Answer:
Explanation: The chemical action that occurs in the cell while the current is flowing causes hydrogen bubbles to form on the surface of the anode. This action is called POLARIZATION. Some hydrogen bubbles rise to the surface of the electrolyte and escape into the air, some remain on the surface of the anode. If enough bubbles remain around the anode, the bubbles form a barrier that increases internal resistance. When the internal resistance of the cell increases, the output current is decreased and the voltage of the cell also decreases.
A cell that is heavily polarized has no useful output. There are several methods to prevent polarization or to depolarize the cell.
One method uses a vent on the cell to permit the hydrogen to escape into the air. A disadvantage of this method is that hydrogen is not available to reform into the electrolyte during recharging. This problem is solved by adding water to the electrolyte, such as in an automobile battery. A second method is to use material that is rich in oxygen, such as manganese dioxide, which supplies free oxygen to combine with the hydrogen and form water.
A third method is to use a material that will absorb the hydrogen, such as calcium. The calcium releases hydrogen during the charging process. All three methods remove enough hydrogen so that the cell is practically free from polarization.
LOCAL ACTION
When the external circuit is removed, the current ceases to flow, and, theoretically, all chemical action within the cell stops. However, commercial zinc contains many impurities, such as iron, carbon, lead, and arsenic. These impurities form many small electrical cells within the zinc electrode in which current flows between the zinc and its impurities. Thus, the chemical action continues even though the cell itself is not connected to a load.
Local action may be prevented by using pure zinc (which is not practical), by coating the zinc with mercury, or by adding a small percentage of mercury to the zinc during the manufacturing process. The treatment of the zinc with mercury is called amalgamating (mixing) the zinc. Since mercury is many times heavier than an equal volume of water, small particles of impurities weighing less than mercury will float to the surface of the mercury. The removal of these impurities from the zinc prevents local action. The mercury is not readily acted upon by the acid. When the cell is delivering current to a load, the mercury continues to act on the impurities in the zinc. This causes the impurities to leave the surface of the zinc electrode and float to the surface of the mercury. This process greatly increases the storage life of the cell.
As a woman walks, her entire weight is momentarily placed on one heel of her high-heeled shoes. Calculate the pressure exerted on the floor by the heel if it has an area of 1.60 cm2 and the woman's mass is 54.0 kg. Express the force in N/m2 and lb/in2. (In the early days of commercial flight, women were not allowed to wear high-heeled shoes because aircraft floors were too thin to resist such large pressures.)
Answer:
P = 3.3075 x 10⁶ N/m² = 479.71 lb/in²
Explanation:
In order to find the pressure , we first need to find the force exerted by the lady. The force must be equal to the weight of the lady:
Force = F = Weight = mg
F = mg = (54 kg)(9.8 m/s²)
F = 529.2 N
Now, we convert area to S.I unit:
Area = A = (1.6 cm²)(1 m/100 cm)²
A = 1.6 x 10⁻⁴ m²
Now, the pressure can be calculated as:
Pressure = P = F/A
P = 529.2 N/1.6 x 10⁻⁴ m²
P = 3.3075 x 10⁶ N/m²
Now, we convert this into lb/in²:
P = (3.3075 x 10⁶ N/m²)[(0.000145038 lb/in²)/(1 N/m²)
P = 479.71 lb/in²
A ball weighing 60 N is swinging like a pendulum at the end of a 6.0 m rope. As the ball swings through its lowest point, its speed is measured at 5.0 m/s. What is the tension in the rope at this point?
A. 58.6 N
B. 85.4 N
C. 90.2 N
D. 97.3 N
Answer:
B. 85.4 N
Explanation:
The tension in the rope at the lowest point of the motion of the ball is antiparallel to the weight of the ball. By Newton's laws we construct the following equation of equilibrium:
[tex]\Sigma F = T - W = \left(\frac{W}{g} \right)\cdot \frac{v^{2}}{L}[/tex] (1)
Where:
[tex]T[/tex] - Tension in the rope, measured in newtons.
[tex]W[/tex] - Weight, measured in newtons.
[tex]g[/tex] - Gravitational acceleration, measured in meters per square second.
[tex]v[/tex] - Speed of the ball, measured in meters per second.
[tex]L[/tex] - Length of the rope, measured in meters.
If we know that [tex]W = 60\,N[/tex], [tex]g = 9.807\,\frac{m}{s^{2}}[/tex], [tex]v = 5\,\frac{m}{s}[/tex] and [tex]L = 6\,m[/tex], then the tension in the rope at this point is:
[tex]T = W+\frac{W\cdot v^{2}}{g\cdot L}[/tex]
[tex]T = W\cdot \left(1+\frac{v^{2}}{g\cdot L} \right)[/tex]
[tex]T = (60\,N)\cdot \left[1+\frac{\left(5\,\frac{m}{s} \right)^{2}}{\left(9.807\,\frac{m}{s^{2}} \right)\cdot (6\,m)} \right][/tex]
[tex]T = 85.492\,N[/tex]
Hence, the correct answer is B.
Joe applies a force of 50 N to a box which has a mass of 15 kg. What is the acceleration of the box?
a.
Answer:
3.333 m/s^2
Explanation:
50/15 = 3.33 m/s^2
Which lists three organic biological molecules?
O carbohydrates, salts, metals
O salts, proteins, minerals,
O proteins, lipids, carbohydrates
O lipids, metals, minerals
Answer:
B
Explanation:
I'm learning it in science.
Answer:
its not b i just took the test and b was wrong
Explanation:
. A pendulum of length l = 9.8 m hangs in equilibrium and is then given velocity
v
=0.2
m/s at its lowest point. What is the amplitude of the subsequent oscillation?
Answer:
the amplitude of the sequence oscillation=
ASO = length × velocity
= 9.8 × 0.2 = 19.6
ASO = 19.6
Which would best help a student determine the net force acting on a rollercoaster car as it moves from one point on its track to another?
Answer:
you can show them a vid
Explanation:
Need help ASAP plsss
Write 5-6 sentences about
:how do parachutes work ??
A ripcord system pulls a closing pin, which releases a spring-loaded pilot chute, and opens the container; from which the parachute comes out.
If a skydiver is unable to open her/his parachute, an automatic activation device will automatically open the parachute.
A parachute works by forcing air into the front of it and creating a structured 'wing' under which the canopy pilot can fly. Parachutes are controlled by pulling down on steering lines which change the shape of the wing, cause it to turn, or to increase or decrease its rate of descent.
identical spheres are dropped from a height of 100 m above the surfaces of Planet X and Planet Y. The speed of the spheres as a function of time is recorded for each planet in the graph
above. Which planet exerts the greater force of gravity on the sphere, and what evidence supports this conclusion?
A Planet X because its line has the greater area under it.
Planet X, because its line has the greater slope
Planet Y. because it falls for the smaller amount of time
Planet Y because the object's final speed is greater
Answer:
B. Planet X, because its line has the greater slope.
Explanation:
In a speed graph, acceleration is slope. A greater slope means a greater acceleration. According to Newton's 2nd law (F=mg), a greater acceleration means a greater force.
Planet X exerts the greater force of gravity on the sphere, because its line has the greater slope. Hence option B is correct.
What is Gravitational Force ?Gravitational force is force of attraction between two masses. Gravitational force(F) between two bodies is directly proportion to the product of masses(m₁,m₂) of two bodies and inversely proportional to square of distance(r) between them. mathematically it is written as,
F ∝ m₁.m₂
F ∝ 1/r²
F = G m₁,m₂÷r²
where G is gravitational constant, whose value is 6.6743 × 10⁻¹¹ m³ kg-1s⁻².
Force is expressed in Newton N in SI unit. its dimensions are [M¹L¹T⁻²].
This is analogous with coulomb's law which gives force between two charges.
if a planet has greater gravitational force(force of gravity), then body falls with greater speed as compare to other planet which is having less force of gravity. we can see in case of planet X there is greater speed as compare to plane Y in short time. Hence option B is correct.
To know more about Gravity :
https://brainly.com/question/31321801
#SPJ2.
A solid disk rotates in the horizontal plane at an angular velocity of 0.649 rpm with respect to an axis perpendicular to the disk at its center. The moment of inertia of the disk is 0.101 kg m2. From above, sand is dropped straight down onto this rotating disk, so that a thin uniform ring of sand is formed at a distance of 0.415 m from the axis. The sand in the ring has a mass of 0.499 kg. After all the sand is in place, what is the angular velocity of the disk
Answer:
The angular velocity of the disk is 0.0369 rad/sec.
Explanation:
Convert 0.649 rpm to rad/s
0.649 rpm = 0.649 * (2π/60) = 0.0679rad/sec
From the question,
Summation of final angular momentum equals summation of initial angular momentum
I*w = Io*wo
w = wo (lo/I)
But I = Isand + Io
and Isand = Msand * R²sand
Therefore, w = wo (lo/I) = wo (Io/Msand * R²sand + Io)
Where,
wo = 0.0679rad/sec
Io = 0.101 kg m2
Msand = 0.499 kg
Rsand = 0.415 m
Hence,
w = 0.0679 {0.101/(0.499*(0.415)²+0.101)}
w = 0.0679 (0.101/0.1869)
w = 0.0679*0.544 = 0.0369 rad/sec
The angular velocity of the disk is 0.0369 rad/sec.
The rate of change of velocity or speed is known as acceleration. If a car increases it speed form 10 to 20m/s in 2 seconds, then what is its rate of change in velocity?
A) 5 m/s/s
B) 10 m/s/s
C) 20 m/s/s
D) 40 m/s/s
Answer:
A) 5 m/s/s
Explanation:
Given the following data;
Initial velocity = 10m/s²
Final velocity = 20m/s²
Time, t = 2 seconds.
In physics, acceleration can be defined as the rate of change of the velocity of an object with respect to time.
This simply means that, acceleration is given by the subtraction of initial velocity from the final velocity all over time.
Hence, if we subtract the initial velocity from the final velocity and divide that by the time, we can calculate an object’s acceleration.
Mathematically, acceleration is given by the equation;
[tex]Acceleration, a = \frac{final \; velocity - initial \; velocity}{time}[/tex]
Substituting into the equation, we have;
[tex]Acceleration, a = \frac{20 - 10}{2}[/tex]
[tex]Acceleration, a = \frac{10}{2}[/tex]
Acceleration, a = 5m/s²
A thyristor (SCR) is a
Answer:
A thyristor (/θaɪˈrɪstər/) is a solid-state semiconductor device with four layers of alternating P- and N-type materials. It acts exclusively as a bistable switch, conducting when the gate receives a current trigger, and continuing to conduct until the voltage across the device is reversed biased, or until the voltage is removed (by some other means).
Explanation:
Correct me if im wrong
A small sphere of mass m and charge –q is released from rest at point T. If the electric potentials at points S and T are VS and VT, respectively, what is the speed of the sphere when it reaches point S? Ignore the effects of gravity.
(A) 2q/m(Vs + VT)
(B) 4q/m(Vs + VT)
(C) q/2m(Vs - VT)
(D) q/2m (Vs + VT)
(E) 2q/m(Vs - VT)
Answer:
(E) √[2q/m(Vs - VT)]
Explanation:
Since the charge -q moves from VT to VS, the potential difference is VT - VS.
The work done in moving the charge q across a potential difference V is given by W = qV.
Now, the work done in moving the charge -q across that potential difference VT - VS is thus W = -q(VT - VS) = -q[-(VS - VT)] = q(VS - VT). This work equals the sphere's kinetic energy and kinetic energy equals K = 1/2mv² where m = mass of sphere and v = speed of sphere.
So, K = W
1/2mv² = q(VS - VT)
v² = 2q/m(VS - VT)
taking square root of both sides, we have
v = √[2q/m(Vs - VT)]
A has a frequency of 300 Hz and a wavelength of 1.10 m. What is the velocity of the wave?
Hello!!
For calculate the Velocity of the wave let's applicate the formula:
[tex]\boxed{V=f*\lambda}[/tex]
[tex]\textbf{Being:}[/tex]
[tex]\sqrt{}[/tex] V = Velocity = ?
[tex]\sqrt{}[/tex] f = Frequency = 300 Hz
[tex]\sqrt{}[/tex] [tex]\lambda[/tex] = Wavelength = 1,1 m
⇒ [tex]\text{Then let's \textbf{replace it according} we information:}[/tex]
[tex]V = 300 \ Hz * 1,1 \ m[/tex]
⇒ [tex]\text{Let's resolve it: }[/tex]
[tex]V = 330 \ m / s[/tex]
[tex]\textbf{Result:}\\\text{The velocity is \textbf{330 meters per second}}[/tex]
Answer:
For calculate the Velocity of the wave let's applicate the formula:
V = Velocity = ?
f = Frequency = 300 Hz
= Wavelength = 1,1 m
⇒
⇒
Explanation:
A ball of mass 4kg moving with a velocity of 20m/s collides with another ball of mass 15kg moving with a velocity of 15m/s in the same direction. Calculate the velocity of the 5kg ball if the collision is perfectly inelastic.
Answer:
velocity = 16.05 m/s
Explanation:
inelastic collision formula:
m1u1 + m2u2 = (m1 + m2)v
m1 = 4kg
u1 = 20m/s
m2 = 15kg
u2 = 15m/s
find v ?
m1u1 + m2u2 = (m1 + m2)v
(4×20) + (15×15) = (4+15)v
80 + 225 = 19v
305 = 19v
19v = 305
v = 305/19
v = 16.05 m/s
You're driving a bumper car at a circus at
18 m/sec, and you hit another car that's at
rest. If you end up going at 6.0 m/sec, what
is the final speed of the other car, given
that both cars have 100.0 kg mass, you
have 80.0 kg mass, and the other person
has a mass of 70.0 kg?
Answer:
PLEASE MARK AS BRAINLIEST!!
Explanation:
ANSWER IS IN THE IMG BELOW
This 200-kg horse ran the track at a speed of 5 m/s. What was the average kinetic energy?
Answer:
2500 JExplanation:
The average kinetic energy can be found by using the formula
[tex]k = \frac{1}{2} m {v}^{2} \\ [/tex]
m is the mass
v is the velocity
From the question we have
[tex]k = \frac{1}{2} \times 200 \times {5}^{2} \\ = 100 \times 25[/tex]
We have the final answer is
2500 JHope this helps you
Using the law of conservation of energy, what is the kinetic energy at e?
Answer:
Send the pic so I can see
You have to move your 100 N couch before a delivery company drops off your new one. Unfortunately your roommate is passed out on it. The coefficient of friction between the couch and floor is .43. It takes 250 N of force to get the couch moving. a) How much does your roommate weigh in Newton’s? b) After you get the couch moving it only takes 200 N to keep it moving at a constant speed, what is the coefficient of kinetic friction?
Answer:
a) Weight of Roommate = 481.4 N
b) μk = 0.34
Explanation:
a)
The force required to move the couch must be equal to the force of friction:
F = frictional force
F = μW
W = F/μ
where,
W = Total Weight of Couch and Roommate
F = Force Required start to move couch = 250 N
μ = coefficient of static friction between couch and floor = 0.43
Therefore,
[tex]W = \frac{250 N}{0.43}\\\\W = 581.4 N[/tex]
So, the total weight is given as:
W = Weight of Couch + Weight of Roommate
Weight of Roommate = W - Weight of Couch
Weight of Roommate = 581.4 N - 100 N
Weight of Roommate = 481.4 N
b)
Now, the force required to keep the couch moving can be given as equal to the kinetic friction force:
F = kinetic friction
F = μk*W
μk = F/W
where,
μk = coefficient of kinetic friction = ?
F = Force required to keep the couch moving = 200 N
Therefore,
μk = 200 N/581.4 N
μk = 0.34
The wave produced by a piano's middle C has a frequency of 440 Hz
and a wavespeed of 344 m/s. What is its wavelength?
Answer:
0.78 m
Explanation:
I just did a hw question for this its just 344 divided by 440
What best describes the speed of light waves in solids, liquids, and gases?
The speed is fastest in solids.
The speed is fastest in liquids.
The speed is fastest in gases.
The speed is the same in all matter.
Answer: It’s fastest in gases. Letter C !
Explanation:
Answer:
its c
Explanation:
Katniss everdeen applies 20 n of force back on her bow what happens to the arrow when she lets go?
52. Serves as an air passageway
a. Oropharynx
c. Nasopharynx
b. Laryngopharynx
d. Larynopharynx
Answer:
Nasopharynx
Explanation:
The nasopharynx is posterior to the nasal cavity and serves only as a passageway for air.