Answer:
a
Explanation:
..................
Which statement best describes energy and matter in a closed system? (2 po
O Energy and matter flow into and out of the system.
Energy can flow into and out of the system but matter cannot.
Energy and matter are contained within a closed system.
O There is no energy in a closed system; there is matter.
Answer:
Energy can flow into and out of the system but matter cannot.
Explanation:
In a closed system, energy can flow in and out of the system but matter cannot.
A closed system prevents double way flow of matter. A closed system conserves matter.For an isolated system, energy and matter cannot flow out of the system.
For open systems, energy and matter can flow out of the system.
Such systems are used for certain thermodynamics experiment.
A potter's wheel is a uniform disk of mass of 10.0 kg and radius 20.0 cm. A 2.0-kg lump of clay, roughly cylindrical with radius 3.0 cm, is placed at the center of the wheel. The wheel initially rotates at 30.0 rev/min. The clay then flattens into a disk of radius 8.0 cm. What is the final angular speed of the wheel?
a. 29.6 rev/min
b. 29.2 rev/min
c. 30.8 rev/min
d. 30.4 rev/min
e. 30.0 rev/min
Answer:
b. 29.2 rev/min
Explanation:
Assuming no external torques acting during the process, total angular momentum must be conserved, as follows:[tex]L_{0} = L_{f} (1)[/tex]
The initial angular momentum L₀, can be expressed as follows:[tex]L_{0} = I_{0} * \omega_{0} (2)[/tex]
where I₀ = initial moment of inertia = moment of inertia of the disk +
moment of inertia of the cylinder and ω₀ = initial angular velocity =
30.0 rev/min.
Replacing by the values, we get:[tex]I_{0} = \frac{1}{2} * m_{d} *r_{d} ^{2} + \frac{1}{2}* m_{c} *r_{c} ^{2} = 0.2 kg*m2 +9e-4 kg*m2 = 0.2009 kg*m2 (3)[/tex]⇒ L₀ = I₀* ω₀ = 0.2009 kg*m² * 30.0 rev/min = 6.027 kg*m²*rev/minThe final angular momentum can be written as follows:[tex]L_{f} = I_{f} * \omega_{f} (4)[/tex]
where If = final moment of inertia = moment of the inertia of the solid
disk + moment of inertia of the clay flattened on a disk, and ωf = final
angular velocity.
Replacing by the values, we get:[tex]I_{f} = \frac{1}{2} * m_{d} *r_{d} ^{2} + \frac{1}{2}* m_{fd} *r_{fd} ^{2} = 0.2 kg*m2 +6.4e-3 kg*m2 = 0.2064 kg*m2 (5)[/tex]
⇒ Lo =Lf = If*ωf
Replacing (2) in (1), and solving for ωf, we get:[tex]\omega_{f} = \frac{L_{o}}{I_{f} } = \frac{6.027kg*m2*rev/min}{0.2064kg*m2} = 29.2 rev/min (6)[/tex]
The rate of change of angular displacement is defined as angular speed. The final angular speed of the wheel will be 29.2 rev/min.
What is angular speed?The rate of change of angular displacement is defined as angular speed. is stated as follows:
ω = θ t
Where,
θ is the angle of rotation,
t is the time
ω is the angular speed
The given data in the problem is
m is the mass of wheel = 10.0 kg
r₁ is the radius of disk = 20.0 cm=0.2
M is the mass of clay= 2.0 kg
R is the radius of cylinder = 3.0cm
[tex]\rm \omega_i[/tex] is the initial rotational speed =30.0 rev/min
r₂ is the final radius of disk= 8.0 cm.
[tex]\rm \omega_f[/tex] is the initial rotational speed=?
When the external torques act on the body is zero the total angular momentum must be conserved, as follows:
Initial momentum = Final momentum
[tex]\rm L_0=L_f[/tex]
The value of the initial angular momentum L₀ is found by
I₀ = initial moment of inertia = moment of inertia of the disk +moment of inertia of the cylinder
[tex]\rm I_0= \frac{1}{2}m_dr_d^2+ \frac{1}{2}m_cr_c^2\\\\ \rm I_0= \frac{1}{2}\times 10\times (0.2)^2+ \frac{1}{2}\times m_2(0.03)^2[/tex]
[tex]\rm L_0 = I_0\times \omega_0\\\\ L_0 = 2009\times 30\\\\ \rm L_0 =6.027 \;kgm^2rev/min[/tex]
The value of the final angular momentum [tex]I_f[/tex] is found by
[tex]\rm I_f= \frac{1}{2}m_dr_d^2+ \frac{1}{2}m_fr_fd^2\\\\ \rm I_0= 0.2064 m_2[/tex]
[tex]\rm I_f[/tex] is the final moment of inertia = moment of the inertia of the solid disk + moment of inertia of the clay flattened on a disk.
[tex]L_0 =L_f = I_f \times \omega_f[/tex]
[tex]\rm \omega_f=\frac{L_0}{I_f} \\\\ \rm \omega_f=\frac{6.027 m_2}{0.2064 m_2} \\\\ \rm \omega_f= 29.2\; rev/min[/tex]
Hence the final angular speed of the wheel will be 29.2 rev/min.
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A 1150 kg car is on a 8.70° hill.
Using X-Y axes tilted down the
plane, what is the y-component
of the weight?
Answer:
Explanation:
y-component = - mgcos(8.7)
= - (1150)(9.81)cos(8.7)
= - 11151.69378
= - 11151.69 N
The weight of the y-component is 11140.33N.
How to find the weight of the y-component?
To find the weight of the y-component:
Given,
Car weight = 1150 kg
Anfle = 8.70 degree
weight = mg = 1150 * 9.8
= 11270 N
Y-component = mg cos∅
= 11270 * cos(8.70)
= 11140.33N
The aspect that pushes proper or left is referred to as the x-factor, and the element that pushes up or down is known as the y-component.
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Mr Jones launches an arrow horizontally at a rate of 40m/s off of a 78.4 m cliff towards the south, what direction and value is his acceleration air resistance is negligible.
A. 9.8 m/s/s west
b. 9.8m/s/s east
C. 9.8m/s's down
d 9.8m/s/s south
Answer:
9.8m/s^2 down (option C)
Explanation:
The only acceleration acting on this motion case in the acceleration due to gravity: 9.8 m/s^2 in the downwards direction.
An object moves at constant speed in a circle. Which of the following is true:
A. A net force in the direction of motion acts on the object.
B. A net force pointing away from the center of the circle acts on the object.
C. A net force pointing towards the center of the circle acts on the object.
D. The net force acting on the object is zero.
If a ball rolls down an incline with a starting velocity of 0m/s and a final velocity of 6m/s
and it takes a total of 1.4 seconds, calculate its acceleration.
Answer:
If a ball rolls down an incline with a starting velocity of 0m/s and a final velocity of 6m/s
and it takes a total of 1.4 seconds, calculate its acceleration.
Answer:
Acceleration is 4.28 m/s²
Explanation:
Acceleration is change of speed in time. To solve this, we will assume that the acceleration is constant, meaning that every second the velocity increases for the same constant value.
a = ∆v/t
∆v is the difference between two measured velocities:
a = (v2 - v1) / t
v1 = 0m/s
v2 = 6m/s
t = 1.4 s
Now, we only plug in the given values:
a = (6 - 0) / 1.4
a = 6 m/s / 1.4 s
a = 4.28 m/s²
pls help quick. the number line shows the starting and ending velocities for ball 1 what's the change in velocity of ball 1 calculate the value mathematically and check using the number line
Answer:
The starting velocity for ball 1 is 1.00 meter/second. Its ending velocity is 0.25 meter/second.
The change in velocity for ball 1 is 0.25 – 1.00 = -0.75 meter/seconds
1. It plays a vital role for self- expression and has been part of rituals
and religious gatherings.
B. Dance
A. Aerobic activity
C. Fitness D. Zumba
Answer:
b.dance
Explanation:
don't know the explanation
What is the force used when a 7 kg bowling ball is rolled with an acceleration of 3 m /s2? Use the formula to find the force in Newtons (N): F = 7 kg × 3 m/s2
Answer:
21 Newtons
Explanation:
Force= mass * acceleration
Force= 7 kg * 3 m/s^2
Force= 21 Newtons
In the Bohr model of the hydrogen atom, an electron in the 1st excited state moves at a speed of 2.19 106 m/s in a circular path having a radius of 5.29 10-11 m. What is the effective current associated with this orbiting electron?
Answer:
I = 1.05x10⁻³ A
Explanation:
By definition, an electric current is the rate of charge flow at a given time:
[tex] I = \frac{q}{t} [/tex]
Where:
q: is the electrons charge = 1.602x10⁻¹⁹ C
t: is the time
In a circular motion, the time is given by:
[tex] t = T = \frac{2\pi}{\omega} = \frac{2\pi}{v/r} = \frac{2\pi r}{v} [/tex]
Where:
ω: is the angular speed = v/r
v: is the speed = 2.19x10⁶ m/s
r: is the radius = 5.29x10⁻¹¹ m
[tex] t = \frac{2\pi r}{v} = \frac{2\pi 5.29 \cdot 10^{-11} m}{2.19 \cdot 10^{6} m/s} = 1.52 \cdot 10^{-16} s [/tex]
Now, the effective current is:
[tex] I = \frac{q}{t} = \frac{1.602 \cdot 10^{-19} C}{ 1.52 \cdot 10^{-16} s} = 1.05 \cdot 10^{-3} A [/tex]
Therefore, the effective current associated with this orbiting electron is 1.05x10⁻³ A.
I hope it helps you!
HELP ASAP!!!
Which graph shows the change in velocity of an object in free fall?
Answer:
the graph that show Change in velocity is no A
The graph that showing the velocity with respect to time for a free falling body is figure C where, the downward velocity will be higher due to the acceleration due to gravity.
What is velocity?Velocity of a moving body is the measure of the distance covered per unit time. Thus, it is the ratio of distance to the time. Velocity is expressed in the units of Km/h, m/s. miles/h, ft./s etc.
The rate of change of velocity is called acceleration. The acceleration by the force of a gravitational field is called acceleration due to gravity g having the value 9.8 m/s².
The velocity - time graph shows a diagonal relation for a free falling body. A free falling body is initially at rest and falls downward with the negative velocity with the acceleration due to gravity. Therefore, figure B shows the change in velocity of a free falling body.
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The chart shows Daniela’s run through her race.
A graph with horizontal axis time (seconds) and vertical axis position in (meters). The line runs straight from 0 seconds 5 meters to 10 seconds 30 meters.
What is her velocity?
1.5 m/s
2 m/s
2.5 m/s
5 m/s
Answer:
Explanation:
velocity is the rate of change of displacement with respect to time.
Velocity = displacement/time
If a line runs straight from 0 seconds 5 meters to 10 seconds 30 meters.
The velocity will be expressed as;
v = d2-d2/t2-t1
v = 30-5/10-0
v = 25/10
v = 2.5m/s
Hence her velocity is 2.5m/s
Daniela's velocity is 2.5 m/s.
Velocity is the ratio of displacement to time taken. It is given by:
Velocity = displacement / time
The velocity of Daniela can be gotten by calculating the slope of the graph. Considering the points (0, 5) and (4, 15).
[tex]Velocity(slope)=\frac{15-5}{4-0}=2.5\ m/s[/tex]
Therefore Daniela's velocity is 2.5 m/s.
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An object accelerates 12.0 m/s2 when a force of 6.0 newtons is applied to it. What is the mass of the object?
Answer:
0.5 kgExplanation:
The mass of the object can be found by using the formula
[tex]m = \frac{f}{a} \\ [/tex]
f is the force
a is the acceleration
From the question we have
[tex]m = \frac{6}{12} = \frac{1}{2} \\ [/tex]
We have the final answer as
0.5 kgHope this helps you
Mr Johnson launches an arrow horizontally at a rate of 40m/s off of a 78.4 m cliff towards the south, how much time does it take before the arrow hits the ground below (step 1 of a quesiton will need this answer for a future question)
a 2 seconds
b. 1 second
c.4 seconds
d 19.6
Answer:c
Explanation:
how long does the guided discovery stage of the drawing in phase last? in training program
Answer:
2 to 3 weeks
Explanation:
What is Newton's universal law of gravitation
Answer:
an object that is in motion wont go out of motion until there is another force pushing on it
What is gravitonal force
Answer:
its something that hold the air for forceing liy by the exgen
Explanation:
why is it more painful to walk on gravel with your shoes off then on (3 marks please)
Answer:
Because shoes protect our feet from some of the most harmful platforms
Gravel has some small pebbles on it sometimes (or other sharp objects)
Gravel is pretty hard.
which state can you infer that average home prices are the highest? Florida California Texas New York
Answer:
California
Explanation:
just took the test
The state you can infer where average home prices are the highest is California. Option B. This is further explained below.
What is an average home price?Generally, an average home price refers to a cumulative average to the house or home pricing in a state.
In conclusion, California has the highest average home prices highest in America.
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Select all correct answers....Covalent compounds
Robin would like to shoot an orange in a tree with his bow and arrow. The orange is hanging yf=5.00 myf=5.00 m above the ground. On his first try, Robin looses the arrow at v0=35.0 m/sv0=35.0 m/s at an angle of θ=30.0°θ=30.0° above the horizontal. The arrow has an initial height of y0=1.50 m,y0=1.50 m, and its tip is x=60.0 mx=60.0 m away from the target orange. Treating the arrow as a point projectile and neglecting air resistance, what is the height of the arrow once it has reached the horizontal position xx of the orange? Use g=9.81 m/s2g=9.81 m/s2 for the acceleration due to gravity.
Answer:
h' = 55.3 m
Explanation:
First, we analyze the horizontal motion of the projectile, to find the time taken by the arrow to reach the orange. Since, air friction is negligible, therefore, the motion shall be uniform:
s = vt
where,
s = horizontal distance between arrow and orange = 60 m
v = initial horizontal speed of the arrow = v₀ Cos θ
θ = launch angle = 30°
v₀ = launch speed = 35 m/s
Therefore,
60 m = (35 m/s)Cos 30° t
t = 60 m/30.31 m/s
t = 1.98 s
Now, we analyze the vertical motion to find the height if arrow at this time. Using second equation of motion:
h = Vi t + (1/2)gt²
where,
Vi = Vertical Component of initial Velocity = v₀ Sin θ = (35 m/s)Sin 30°
Vi = 17.5 m/s
Therefore,
h = (17.5 m/s)(1.98 s) + (1/2)(9.81 m/s²)(1.98 s)²
h = 34.6 m + 19.2 m
h = 53.8 m
since, the arrow initially had a height of y = 1.5 m. Therefore, its final height will be:
h' = h + y
h' = 53.8 m + 1.5 m
h' = 55.3 m
Why are the coral reefs suffering? (site 2) explain
Answer:
bcuz ov yo fat mamma
Explanation:
Answer:
Water pollution
Explanation:
I WILL GIVE BRAILYEST!!! What is the mass of an object moving at a velocity of 5 m/s if the momentum of the object is 50 kg•m/s?
a. 250 kg
c. 10 Kg
b. .002 Kg
d. 45 Kg
Answer:
a. 250kg I think it's the right answer. hope it helps:)
Answer:
C.10
Explanation:
because when you divide 50 divided by 5 = 10
9. What distance is a book from the floor if the book contains 196 Joules of potential energy and has a mass of 5 kg?
Answer:
the book is 4 meters from the floor
Explanation:
Use the formula for potential energy:
U = m g h
196 J = 5kg 9.8m/s^2 h
h = 196 / (5*9.8 ) m
h = 4 m
What is the acceleration of gravity, in m/s2, on the surface (or outer limit) of Venus? The mass of Venus is 4.87 1024 kg and its radius is 6.05 106 m.
Answer:
8.9 m/[tex]s^{2}[/tex]
Explanation:
From Newton's law of universal gravitation,
F = [tex]\frac{GMm}{R^{2} }[/tex] .............. 1
and from Newton's second law of motion,
F = mg ........... 2
Equating the two expression,
mg = [tex]\frac{GMm}{R^{2} }[/tex]
g = [tex]\frac{GM}{R^{2} }[/tex]
Given that: mass of Venus = 4.87 x [tex]10^{24}[/tex] Kg, radius = 6.05 x [tex]10^{6}[/tex] and G = 6.67 x [tex]10^{-11}[/tex] N[tex]m^{2} Kg^{-2}[/tex]
Thus;
g = [tex]\frac{6.67*10^{-11}*4.87*10^{24} }{(6.05*10^{6} )^{2} }[/tex]
= [tex]\frac{3.24829*10^{14} }{3.66025*10^{13} }[/tex]
= 8.87450
g = 8.9 m/[tex]s^{2}[/tex]
the acceleration of gravity on the surface of Venus is 8.9 m/[tex]s^{2}[/tex].
which refers to information gathered by the systematic study of nature?
prediction
communication of facts
scientific knowledge
hypothesis
Answer:
it is scientific knowledge
Explanation:
got i right on edge
The scientific knowledge refers to information gathered by the systematic study of nature.
What is scientific knowledge?A generalized corpus of laws and ideas developed employing the scientific method to describe an interesting occurrence or behavior is referred to as scientific knowledge.
What is systematic study?
Science would be the systematic study of the composition and dynamics of the physical as well as the natural world via experimentation and observation.
the systematic study of natural circumstances and phenomena. empirical proof. the term for the facts and figures that support an explanation in science.
Therefore, the correct answer will be option (C)
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Experiment: Gravity
Potential Energy = Force x Distance
To show you how this works, study the following example.
If the washers had a mass of 2 grams, and since the force due to gravity in the metric system is 9.8 m/sec2, the weight would be:
W = mass (kg) x gravity
W = 0.002 kg x 9.8 = 0.0196 Newton's. The Newton (N) is the measure of force (or weight here) in the metric system.
The next phase of the computation is to determine the difference in potential energy between where the washers originally started from and the energy of the new position. If the washers were originally 1 meter from the floor or desktop, and the magnet raised them 1 centimeter, the difference in distance raised will be 1 cm, or 0.01 m. Therefore, the potential energy change will be:
Force x Distance = Potential Energy
(0.0196 N) x (0.01 m) = 0.000196 Nm (or Joules)
The magnet is changing the potential energy of the washers by 0.000196 J, or in scientific notation:
1.96 x 10-4 J.
Answer: the washer would slow down depending on how strong the magnet is even though the gravitational pull is the same. the change would be .6
Explanation: i don't really get it
A 4.00-kg particle moves along the x axis. Its position varies with time according to x= 5t +1 2.0t^3, where x is in meters and t is in seconds. Find:
a. the kinetic energy of the particle at any time t.
b. the acceleration of the particle and the force acting on it at time t.
c. the power being delivered to the particle at time t.
d. the work done on the particle in the interval t = 0 to t =5
Answer:
a) The kinetic energy of the particle at any time t is [tex]K = 50+120\cdot t^{2}+72\cdot t^{4}[/tex].
b) The acceleration of the particle at time t is [tex]a= 12\cdot t[/tex]. The force acting on the particle at time t is [tex]F = 48\cdot t[/tex].
c) The power being delivered to the particle at time t is [tex]\dot W = 240\cdot t +288\cdot t^{3}[/tex].
d) The work done on the particle in the interval t = 0 to t = 5 is 48000 joules.
Explanation:
a) The kinetic energy of the particle is entirely translational, whose formula is:
[tex]K = \frac{1}{2}\cdot m \cdot v^{2}[/tex] (1)
Where:
[tex]K[/tex] - Translational kinetic energy, measured in joules.
[tex]m[/tex] - Mass of the particle, measured in kilograms.
[tex]v[/tex] - Velocity of the particle, measured in meters per second.
The velocity of the particle is the rate of change of the position of the particle in time, that is:
[tex]v = 5+6\cdot t^{2}[/tex] (2)
Where [tex]t[/tex] is the time, measured in seconds.
By substituting on (1), we have the following expression: ([tex]m = 4\,kg[/tex])
[tex]K = 2\cdot (5+6\cdot t^{2})^{2}[/tex]
[tex]K = 2\cdot (25+60\cdot t^{2} +36\cdot t^{4})[/tex]
[tex]K = 50+120\cdot t^{2}+72\cdot t^{4}[/tex]
The kinetic energy of the particle at any time t is [tex]K = 50+120\cdot t^{2}+72\cdot t^{4}[/tex].
b) The acceleration of the particle is the rate of change of the velocity of the particle in time, that is:
[tex]a= 12\cdot t[/tex] (3)
Where [tex]a[/tex] is the acceleration of the particle, measured in meters per square second.
The acceleration of the particle at time t is [tex]a= 12\cdot t[/tex].
The force is obtained by multiplying (3) by the mass of the particle. That is to say: ([tex]m = 4\,kg[/tex])
[tex]F = m\cdot a[/tex] (4)
[tex]F = 48\cdot t[/tex]
The force acting on the particle at time t is [tex]F = 48\cdot t[/tex].
c) According to the Work-Energy Theorem, the change in kinetic energy of the particle equals the change in the net work done on the particle. In this case, the power is equal to the rate of change in kinetic energy.
[tex]\dot W = \dot K[/tex] (5)
[tex]\dot W = \frac{d}{dt}(50+120\cdot t^{2}+72\cdot t^{4})[/tex]
[tex]\dot W = 240\cdot t +288\cdot t^{3}[/tex]
The power being delivered to the particle at time t is [tex]\dot W = 240\cdot t +288\cdot t^{3}[/tex].
d) The work done on the particle ([tex]W[/tex]), measured in joules, is equal to the change of the kinetic energy of the particle:
[tex]W = K(5)-K(0)[/tex] (6)
[tex]W = [50+120\cdot (5)^{2}+72\cdot (5)^{4}]-[50+120\cdot (0)^{2}+72\cdot (0)^{4}][/tex]
[tex]W = 48000\,J[/tex]
The work done on the particle in the interval t = 0 to t = 5 is 48000 joules.
Mr Jones launches an arrow horizontally at a rate of 40m/s off of a 78.4 m cliff towards the south, how far south does the arrow travel. (Step 2, you need the previous questions answer to answer correctly
a. 118.4 m south
b 1936 m south
C 2 m south
d 640 m south
Answer:c
Explanation:its the answer because its the answer
what are the formulae of momentun and their time of use
Answer:
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