Answer:
Explanation:
Because the total energy available to the ball doesn't change whatsoever during its entire trip from the window to the ground,
TE = KE + PE which says that the total energy available to a system is equal to the kinetic energy of the system plus the potential energy, and that this value will not ever change (because energy cannot be created or destroyed. Sound familiar?) If the ball is being held still before it is dropped from some height off the ground, it is here that the total energy can be determined, and that total energy at this point is all potential, since the ball is not moving while someone is holding it and getting ready to drop it. The SECOND it starts to fall, the potential energy begins to be converted to kinetic. As the potential energy is losing value, the kinetic is gaining it at the same rate (again, energy doesn't just disappear; it has to go somewhere. Here, it goes from potential to kinetic a little at a time). When the ball finally hits the ground, or an INSTANT BEFORE it hits the ground, the potential energy is 0 because the height of something on the ground has a height of 0. At this instant, right before the ball hits the ground, is where the KE is the greatest. All the energy at that point has been converted from potential to kinetic.
Long story short, choice B is the one you want.
skater spins over a point at a speed of 3.0 rotations per second then the momentum of inertia is 0.60 kg.M2, what is its angular momentum?
Answer:
[tex]L=11.3\ kg-m^2/s[/tex]
Explanation:
Given that,
Angular speed of a skater, [tex]\omega=3\ rot/s=18.84\ rad/s[/tex]
The moment of inertia of the skater, I = 0.6 kg-m²
We need to find the angular momentum of the skater. The formula for the angular momentum of the skater is given by :
[tex]L=I\omega[/tex]
Substitute all the values,
[tex]L=0.6\times 18.84\\\\L=11.3\ kg-m^2/s[/tex]
So, its angular momentum is equal to [tex]11.3\ kg-m^2/s[/tex].
The illustration in figure below shows a uniform metre rule weighing 30 N pivoted on a wedge placed under the 40 cm mark and carrying a weight of 70 N hanging 2 from the 10 cm mark. The ruler is balanced horizontally by a weight W hanging from the 100 cm mark. Calculate the value of the weight W.
Answer:
W = 30 N
Explanation:
Applying the summation of torques about the wedge for equilibrium, taking the clockwise direction as negative. Since the ruler is balanced horizontally about the wedge. Therefore, the summation of all torques acting about the wedge must be equal to zero.
[tex](70\ N)(40\ cm - 10\ cm)-(30\ N)(50\ cm-40\ cm)-(W)(100\ cm - 40\ cm) = 0\\W(60\ cm) = (70\ N)(30\ cm)-(30\ N)(10\ cm)\\\\W = \frac{1800\ N.cm}{60\ cm}[/tex]
W = 30 N
A 140 g tennis ball travelling 30° east of north at 15 m/s is struck by a tennis racquet, giving it a velocity of 25 m/s, west. What are the magnitude and direction of the impulse given to the ball? Include a labelled diagram.
Answer:
The magnitude of the impulse is 1.4 Ns in the West direction.
Explanation:
The impulse equation is given by:
[tex]\Delta p=m\Delta v[/tex]
Where:
m is the mass of the ballΔv is the difference in velocitySo we will have:
[tex]\Delta p=0.140(25-15)[/tex]
[tex]\Delta p=1.4\: Ns[/tex]
Therefore, the magnitude of the impulse is 1.4 Ns in the West direction.
I hope it helps you!
Use Newton's second law of motion and a free-body diagram to...
1. ...calculate the normal force acting upon a 50-kg passenger who accelerates upward at a rate of 3.0 m/s/s.
2. ...calculate the normal force acting upon a 50-kg passenger who accelerates downward at a rate of 3.0 m/s/s.
Please don't put any links or I will report you.
help.....please science
Answer:
please mark me brainliest
Explanation:
ohm
The SI-derived unit of electric resistance is the ohm, which is defined as a volt per ampere.
Answer:
I cant see that
A 12 kg ball is rolling with a velocity of 10 m/s. How much kinetic energy does the ball have?
Answer:
600 J
Explanation:
KE = 1/2 mv^2
Which way does the weight point in an FBD?
the answer would depend on the motion of the object
down
perpendicular to the surface
up
Answer:
the answer would depend on the motion if the surface
who is the first physicist and what did he invented?
Answer:
hippocrates
I guess..........
An electromagnet is a device that uses an electric current to produce a magnetic field.
Electromagnets are typically composed of a piece of metal wrapped with wire and connected to a battery. The battery provides the electric current, and the loops or coils of wire enhance the magnetic field. The more loops there are, the stronger the magnetic field.
When electric current flows through the electromagnet, the metal core becomes magnetized, so it possesses a north pole and a south pole.
Motors place electromagnets inside of permanent magnets as shown below.
However, motors are designed so that the polarity of the electromagnet constantly flips. That is, the north pole becomes the south pole, and the south pole becomes the north pole, every time the electromagnet turns 180 degrees.
Why is it designed this way?
A.
to conserve the energy in the battery
B.
to constantly polarize the field magnet
C.
so the electromagnet will continuously turn
D.
so the magnetic field will get stronger
The reason why motors are designed so that the polarity of the electromagnet constantly flips.is
C. so the electromagnet will continuously turn
Why is motor designed that wayThe reason motors are designed so that the polarity of the electromagnet constantly flips is to continuously turn the electromagnet. This allows the motor to rotate continuously, rather than becoming stuck in one position.
The flipping of the polarity causes the electromagnet to attract and repel from the permanent magnets, creating a rotating motion.
Therefore, the correct answer is C.
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Which of these statements explains why we have day and night? [1] The Earth orbits the Sun once a day The Sun orbits the Earth once a day. The Sun spins on its axis once a day. The Earth spins on its axis once a day.
Answer:
The Earth spins on its axis once a day.
Explanation:
In simple words,The Earth revolves on its axis once every 24 hours and circles the sun once every 365 days. The Earth's rotation on its axis, not its orbit throughout the sun causes day as well as night. The word 'one day' refers to the period it requires the Earth to spin entirely on its axis, which involves both day as well as night.
Which beach balls have potential energy and not kinetic energy?
Answer:
Beach ball 4
Explanation:
it is because, Potential Energy = M G H
P(e) directly proportional to H.
if H increase then P energy also increases
William took a 7 hour bicycle trip. In all, he traveled 112 miles. What was his average rate of speed in miles per hour?
Answer:
16 miles
Explanation:
112 miles/ 7 hours= 16 miles per hour
An object has a mass of 10grams and a volume of 20m3. what is the density of the object
Explanation:
density = mass/ volume
in the question the mass is given in grams so will convert it into kg,
10 g = 0.01 kg
density= 0.01/ 20 = 1 / 2000 = 0.005 kg/m^3
How is it possible a plant can sustain itself for 70 years locked inside a jar ?
Answer:
If you are talking about the experiment in which mouse and plants are kept in a closed glass jar in sunlight so in that case, they both survive because the CO2 released by the respiration of mouse is being utilized by the plants and fixed ( phosynthesis) and O2 is released as by product, which is taken by the mouse for respiration.
A child drops a bouncy ball. Each time it bounces, it reaches a lower height until it eventually
stops. Describe the energy transfers and explain why the ball lowered in height
Answer:
the ball's was lowered because of the gravitational force and because of the friction force's
Why does the golf ball sink in
water, while the beach ball
floats?
A- The beach ball weighs less than
the golf ball
B- The golf ball has a higher density
than the beach ball
C- The beach ball has a higher
density than the golf ball
D- The golf ball has more mass than
the beach ball
Una carga de 4 nC es transportada desde el suelo hasta la superficie de una esfera cargada con un trabajo de 7 X 10-5 j. Determinar el potencial eléctrico de la esfera
Respuesta:
2 × 10⁴ V
Explicación:
Paso 1: Información provista
Carga transportada (q): 4 nCTrabajo realizado (W): 7 × 10⁻⁵ JPaso 2: Convertir q a Coulomb
Usaremos el factor de conversión 1 C = 10⁹ nC.
4 nC × 1 C/10⁹ nC = 4 × 10⁻⁹ C
Paso 3: Calcular el potencial eléctrico (V) de la esfera
Usaremos la siguiente fórmula.
V = W/q
V = 7 × 10⁻⁵ J/4 × 10⁻⁹ C = 2 × 10⁴ V
True or False. The Magnitude of the induced voltage in a coil of wire depends on how quickly the magnetic flux through the coil of wire changes.
Answer:
Yes, its true
Explanation:
hdheheishdhieijzuwhs
Answer: yes its true
Explanation:
nmo
What is a pulley and the how does it make lifting heavy loads easier?
Our entire ______ _____
is built in the backbone of metals.
Answer:
modern world
Explanation:
If a body is thrown up with an initial velocity 'u' and covers a maximum height of 'h' , then 'h' is equal to u²/2g
Explain in detail.
Answer:
1/2 m u^2 initial Kinetic Energy of body
m g h Potential Energy body attains as it rises to height
1/2 m u^2 = m g h conversion of KE to PE
h = u^2 / ( 2 g)
If you're the white mouse, what will you do in order for you to survive
Answer:
If I was the white mouse, I would either find somewhere to hide that matches my fur color to camoflouge with or dig into the dirt so less visible.
To find white colour habitat.
What will I do for my survival?If I was the white mouse, I would find white colour place for living because in that white colour the predators can't see me and i will be safe from them so we can conclude that finding white colour habitat is the best choice to safe myself.
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A specified volume of space contains an electric field for which the magnitude is given by E=E0cos(ωt). Suppose that E0 = 20 V/m and ω = 1.0 × 107 s−1. What is the maximum displacement current through a 0.40 m2 cross-sectional area of this volume?
Answer: [tex]0.708\ mA[/tex]
Explanation:
Given
[tex]E_o=20\ V/m[/tex]
[tex]\omega =10^7\ s^{-1}[/tex]
Cross-sectional area [tex]A=0.40\ m^2[/tex]
Current density is given by
[tex]J=\epsilon_o \dfrac{dE}{dt}[/tex]
Displacement current
[tex]\Rightarrow I=JA\\\Rightarrow I=8.854\times 10^{-12}\times 20\times 10^7\times 0.4\\\Rightarrow I=0.708\times 10^{-3}\ A[/tex]
The required value of the maximum displacement current of the given space is [tex]7.08 \times 10^{-4} \;\rm A[/tex].
Given data:
The intensity of electric field is, [tex]E_{0}=20 \;\rm V/m[/tex].
The angular frequency of electric field is, [tex]\omega=1.0 \times 10^{7} \;\rm s^{-1}[/tex].
The cross-sectional area of space is, [tex]A =0.40 \;\rm m^{2}[/tex].
In the given problem, the instantaneous electric field is given by [tex]E = E_{0} \times cos(\omega t)[/tex]
So, the expression for the current density is,
[tex]J= \epsilon_{0} \times \dfrac{dE}{dt}[/tex]
Here, [tex]\epsilon_{0}[/tex] is the permittivity of free space. Solving as,
[tex]J= \epsilon_{0} \times \dfrac{d(E_{0} \times cos(\omega t))}{dt}\\\\J= -\epsilon_{0} \times E_{0} \times \omega \times sin(\omega t)[/tex]
And the expression for the maximum displacement current is,
[tex]I = J \times A[/tex]
And the maximum displacement current is possible only when, J is positive and J will be positive for [tex]sin(\omega t)=-1[/tex].
Then solving as,
[tex]I = (-\epsilon_{0} \times E_{0} \times \omega \times sin(\omega t)) \times A\\\\I = (-8.85 \times 10^{-12} \times 20 \times (1.0 \times 10^{7}) \times (-1)) \times 0.40\\\\I = 7.08 \times 10^{-4} \;\rm A[/tex]
Thus, we can conclude that the required value of the maximum displacement current of the given space is [tex]7.08 \times 10^{-4} \;\rm A[/tex].
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Select the correct answer.
What does AC stand for in physics?
O A. alternating current
OB. alternative circuit
OC. alternating composition
OD. all charge
How does the motion of the molecules change when you increase the temperature
Answer:
They speed up as temperature increases.
Explanation:
As temperatures increases within a molecule the particles will speed up.
2. Give at least 2 major roles of mining in our lives.
Answer:
Mined materials are needed to construct roads and hospitals, to build automobiles and houses, to make computers and satellites, to generate electricity, and to provide the many other goods and services that consumers enjoy.
Explanation:
a vehicle is moving with 20m/s towards the east and another is moving 15m/s towards the west
Answer:
5 m/s
Explanation:
Given that,
A vehicle is moving with 20m/s towards the east and another is moving 15m/s towards the west.
It is assumed to find the resultant velocity of the vehicle. Let east side is positive and west is negative. So,
[tex]v=v_1+v_2\\\\=20+(-15)\\\\=5\ m/s[/tex]
Hence, the resultant velocity of the vehicle is equal to 5 m/s.
Which is closest to the Earth?
A. Moon
B. Sun
C. Mars
D. Venus
Answer:
A. Moon
Explanation:
The Moon is hundreds of thousands of miles away from the Earth while the other options are hundreds of millions of miles away.
How are frequency and period related?
They are directly related.
They are inversely related.
They aren't related.
Bajo la acción del viento una puerta gira un ángulo de 90° en 5 s. Calcular su velocidad angular y la velocidad lineal de los puntos del borde
si el ancho de la puerta es de 50 cm. R. 0,314 rad/s, 0,157 m/s.
