Hi there!
[tex]\boxed{\text{Her angular velocity decreases.}}[/tex]
Recall the conservation of angular momentum:
[tex]L_i = L_f\\\\I_iw_i = I_fw_f[/tex]
When this person extends her arms, her moment of inertia increases.
According to the conservation of angular momentum, if the moment of inertia increases, the angular velocity must DECREASE.
An object of mass of 2.0 kg rotates at constant speed in a horizontal circle of radius 5.0 m. The time
for one complete revolution is 3.0 s. What is the magnitude of the resultant force acting on the object.
Explanation:
follow the above attachment to get the answer.
A small sphere 0.70 times as dense as water is dropped from a height of 8 m above the surface of a smooth lake. Determine the maximum depth to which the sphere will sink. Neglect any energy transferred to the water during impact and sinking.
Answer:
18.66m
Explanation:
This was actually fun! Let set up the problem first: As you drop the sphere, it will accelerate till it hits the water with a given speed [tex]\dot z[/tex]. Once sinking the ball is subjected to two forces: its own weight [tex]m_sg = \rho_sVg[/tex] directed towards the bottom of the lake, and buoyancy (Archimedes law), ie a force upward equal to the volume of displaced water, [tex]m_wg=\rho_wVg[/tex]. At this point it's the classical "how high can I toss a ball before it falls down" with a water twist. Please note that I'm using z as the height of the sphere, and [tex]\dot z; \ddot z[/tex] represent the velocity (with one dot) and the acceleration (with two dots) in the z direction .Let's assume the sign of all quantities being positive if directed upwards, and negative if towards the bottom of the lake.
Let's first determine how fast the ball hit the water. For me the easiest way is saying "at 8m it has a given potential energy, and 0 kinetic energy. When it hits the water it loses all potential energy and has only kinetic energy". In numbers:
[tex]m_sgz=\frac12m_s\dot z_0^2[/tex] Let's divide by the masses, g is a known value ([tex]9.81 ms^{-2}[/tex]), z is 8 meters, and we get that [tex]\dot z_0 = 4\sqrt g =12.52 m/s[/tex]
At this point, let's determine the force acting on the sphere, courtesy of Newton second law and the debate we had earlier:
[tex]m_s \ddot z = -m_sg + m_wg\\\rho_sV \ddot z = -\rho_sVg + \rho_wV g[/tex]
At this point we can divide by the volume of the sphere, and make use of the fact that [tex]\rho_s = 0.7 \rho_w[/tex]
[tex]0.7\rho_w \ddot z = -.7\rho_w g+ \rho_wg \rightarrow 0.7 \ddot z = 0.3 g\\\ddot z = \frac {0.3}{0.7} g= \frac 37g = 4.2 ms^-2[/tex]
We're almost there. At this point we can write the law of motion for the sphere.
[tex]\dot z = \dot z_0 + \ddot z t[/tex] that we will use to find the time for the ball to stop sinking - ie reaches 0 velocity.
[tex]0 = -12.52 +4.2t \rightarrow t= 12.52/4.2 \approx 3s[/tex]
At this point we can use the other law of motion to find out the distance traveled
[tex]z= z_0 + \dot z_ot + \frac12 \ddot z t^2\\z= 0 -12.52 (3) + \frac12 (4.2)(3)^2 = -37.56+18.90 = -18.66 m[/tex]
as usual, please double and triple check all the calculations, it's almost 1.30 am here and I am not the most confident number cruncher even when fully awake.
20 examples of electropositive radical
A wooden block moves at a constant speed on a rough horizontal surface. Draw a free-body diagram
clearly showing all the forces applied to the block; compare their magnitudes and directions.
The weight of the block and normal reaction are equal in magnitude but opposite in direction. Also, the frictional force and applied force are equal in magnitude but opposite in direction.
The forces acting on the wooden block moving at a constant speed include the following;
weight of block acting downwards, Wnormal reaction on the block acting upwards, Napplied force on the block acting towards positive x-direction, Ffrictional force acting towards negative x-direction, [tex]F_f[/tex]The free-body diagram is presented below;
N
↑
[tex]F_f[/tex] ← ⊕ → F
↓
W
The block is moving at a constant speed, we will have the following;
[tex]W = N \\\\F = F_f[/tex]
Thus, we can conclude that the weight of the block and normal reaction are equal in magnitude but opposite in direction. Also, the frictional force and applied force are equal in magnitude but opposite in direction.
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give to examples of electrical energy being transformed into light?
Answer:
A lightbulb is connected to an outlet that has a source of electricity. The electrical energy is converted into light energy to allow the bulb to glow.
Explanation: Lightning is a discharge of static electricity. The lightning bolt lights up the sky.
the ground wire on a household circuit is typically what color
Answer:
Hey mate....
Explanation:
This is ur answer.....
Green & YellowHope it helps!
Brainliest pls!
Follow me! :)
The ground wire on a household circuit is green in color in a typical household
What is an electric charge?Charged material experiences a force when it is subjected to an electromagnetic field due to the physical property of electric charge. You can have positive or negative electric charges (commonly carried by protons and electrons respectively). opposing charges attract one another whereas similar charges repel one another. We refer to an object as neutral if it has no net charge.
The charge on one electron is -1.6 ×10⁻¹⁹ coulomb.
The ground wire is either bare or has green insulation in most residential branch circuit cables in the US.
The norm in Europe and the UK is
live, brown
neutral is blue.
stripes with green and yellow: earth.
Thus,the ground wire on a household circuit is green in color in a typical household
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The internal energy is the total kinetic energy and __________ energy of all the particles that make up a system. What word completes the sentence?
Answer:
Potential
Explanation:
The internal energy is the total amount of kinetic energy and potential energy of all the particles in the system. When energy is given to raise the temperature, particles speed up and gain kinetic energy.
Hope this helps :)
A stomp rocket takes 3.1 seconds to reach its maximum height.
What was its maximum height?
Answer:
height where rocket goes
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[tex]\purple{\rule{45pt}{7pt}}\blue{\rule{45pt}{999999pt}}[/tex]
[tex]\purple{\rule{45pt}{7pt}}\blue{\rule{45pt}{999999pt}}[/tex]
[tex]\purple{\rule{45pt}{7pt}}\blue{\rule{45pt}{999999pt}}[/tex]
[tex]\purple{\rule{45pt}{7pt}}\blue{\rule{45pt}{999999pt}}[/tex]
A car starts from rest and for 15.0 s its wheels has a constant linear acceleration of 0.800 m/s^2 to the right. What is the angle through which each wheel rotated in 20.0 s interval if the radius of the tires is 0.330 m?
[tex] \huge \mathcal{Question}[/tex]
Can someone Help me with this question ?
(I need proper Explanation if possible)
Thanks for Answering ~
Answer:
c. Force applied is 75 N
EDITED
tan 37 = a/g
a = 3g/4
a in equation
t× 3/5 = 2 × 3g/4
t = 5× 10/2
t = 25n
f = ma
f = ( mt + mb )a
F = 10 × 3× 10/4
F = 75 n
• Correct option is (C).
We know that the angle made by string is θ=
[tex]tan {}^{ - 1} ( \frac{a}{g} )[/tex]
where a is the acceleration of the frame in which the string is hanging in our case it is a trolley.
[tex]putting \: θ=37° \: or \: tan \: 37° = \frac{3}{4} [/tex]
[tex]we \: get \: a \: \frac{3g}{4} = \frac{30}{4} = 7.5 \: m/s^2[/tex]
[tex] \boxed{Force \: F=total \: mass \: of \: the \: system \: on \: which \: force \: is \: acting ×acceleration \: of \: the \: system=(8+2)×7.5=75 }[/tex]
[tex] \boxed{ so \: force \: is \: 75 \:N. }[/tex]
A 68 g plastic ball is moving to the left at 17 m/s . How much work must be done on the ball to cause it to move to the right at 17 m/s ?
Answer:
KE = 19.652 J to the right
Explanation:
KE = J or N*m
KE = (1/2)m*v²
KE = kinetic energy
m = mass(kg)
v = velocity (m/s)
KE = .5*0.068kg*(17m/s)²
KE = 9.826 J to the left
So double it to the right to get 17m/s.
KE = 19.652 J to the right
J = Joules or can be expressed as N*m which is Newton-meters.
Cho mạch điện gồm ba điện trở mắc nối tiếp nhau. Biết R 1 = 8Ω, R 2 = 12Ω, R 3 = 4Ω. Hiệu điện thế giữa hai đầu đoạn mạch U = 48V. Tính hiệu điện thế giữa hai đầu mỗi điện trở.
56gq2391$/= 343568
hope u understand me
What nation recently blew up one of its own satellites as part of a missile test, triggering a warning from the u.s. over a potentially dangerous debris field?
Answer:
Russia
Explanation:
my answer was deleted for no reason. apparently i was violating community guidelines when i wasnt. anyways, the answer is russia...
What do scientists call a substance that contains atoms from two or more different elements that are chemically bonded?
Atom
Compound
Element
Molecule
As a speaker, I should know my purpose and method of delivery before giving my speech so...
Explanation:
I will prepare my speech first and then I will give a speech on it.
In a titration, 50.00 cm3 of 0.300 mol/dm3
sodium hydroxide solution is exactly neutralized by 25.0
cm3 of a dilute solution of hydrochloric acid.
NaOH(aq) + HCl(aq) → NaCl(aq) + H2O(l)
Calculate the concentration of the hydrochloric acid. Show your work out
PLS URGENT ANS
Answer:
Step 1: Calculate the amount of sodium hydroxide in moles
Volume of sodium hydroxide solution = 50.0 ÷ 1,000 = 0.05 dm3
Rearrange:
Concentration in mol/dm3 = amount of solute in molvolume in dm3
Amount of solutein mol = concentration in mol/dm3 × volume in dm3
Amount of sodium hydroxide = 0.300 × 0.05
= 0.01 5mol
Step 2: Find the amount of hydrochloric acid in moles
The balanced equation is: NaOH(aq) + HCl(aq) → NaCl(aq) + H2O(l)
So the mole ratio NaOH:HCl is 1:1
Therefore 0.015 mol of NaOH reacts with 0.015 mol of HCl
Step 3: Calculate the concentration of hydrochloric acid in mol/dm3
Volume of hydrochloric acid = 25.00 ÷ 1000 = 0.025 dm3
Concentration in mol/dm3 = amount of solute in molvolume in dm3
Concentration in mol/dm3 = 0.015/0.025
= 0.6 mol/dm3
Step 4: Calculate the concentration of hydrochloric acid in g/dm3
Relative formula mass of HCl = 1 + 35.5 = 36.5
Mass = relative formula mass × amount
Mass of HCl = 36.5 × 0.6
= 21.9 g
So concentration = 21.9 g/dm3
foetus grows by receiving nutriens and oxygen from the mother. How does the foetus receive these nutriens and oxygen?
Answer:
From the very beginning, the developing cells need oxygen and nutrients. The fetus receives its nutrition from the mother through the placenta and the umbilical cord.
Explanation:
I'LL MARK YOU BRAINLIST ......By referring to the graph shown below, the acceleration from t = 0 s to t = 25 s is:
positive
negative
zero
increasing
Answer:
When an object is speeding up, the acceleration is in the same direction as the velocity. Thus, this object has a positive acceleration. In Example B, the object is moving in the negative direction (i.e., has a negative velocity) and is slowing down.
Explanation:
Answer:
It’s zero.
Explanation:
It’s a straight line so its at a rest.
A SMART car can accelerate from rest to a speed of 28 m/s in 20s. What distance does it travel in this time?
The coefficient of kinetic friction between a couch and the floor is .81 if the couch has a mass of 71 kilograms and you push it with a force of 650 newtons what is the net force on the couch as it slides
Hi there!
The equation for the kinetic friction force is:
[tex]F_{kf} = \mu mg[/tex]
We can begin by doing a summation of forces acting on the couch where a positive force is in the direction of the couch's acceleration, or in the direction of the push.
Thus:
[tex]\Sigma F = F_A - F_{kf}[/tex]
Now, plug in the values:
[tex]F_{net}= 650 - (.81 * 9.8 * 71) = \boxed{86.4 N}[/tex]
in an rfid system, where would the unique data identifying an item typically be found?
In a radio frequency identification (RFID) system, the unique data identifying an item are typically found in: tags.
What is an RFID system?
RFID is an acronym for radio frequency identification.
A RFID system can be defined as an automatic, wireless, identification technology (device) that is typically designed to allow end users store and retrieve information, especially through the use of an electromagnetic field.
The operational benefits of an RFID system:
Generally, a radio frequency identification (RFID) system is used for the following:
1. To identify an item or individual.
2. To trace and tracking an item or individual.
3. To track an item or individual.
The components of an RFID system:
An RFID system is a wireless, identification technology (device) that comprises two (2) main components and these are:
ReadersTagsTags refer to small objects containing an antenna and a chip (smart barcodes) that are used to automatically identify an item or individual they are embedded in or attached to.
In conclusion, the unique data that are used in identifying an item are typically found in tags.
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Mention the methods of census and explain each of them in brief
Answer:
Census includes the total process of collecting, compiling, analyzing, evaluating, publishing and disseminating statistical data regarding the population and housing and their geographical location. Population characteristics include demographic, social and economic data and are provided as of a particular date (reference period).
Census Methods:
Population censuses typically use one of two approaches:
De facto – meaning enumeration of individuals as of where they are found in the census, regardless of where they normally reside.
De jure - meaning enumeration of individuals as of where they usually reside, regardless of where they are on census day.
Josh and jake are both helping to build a brick wall which is 6 meters in height. They each lay 250 bricks, but josh finishes this task in 3 hours while jake requires 4.5 hours to complete his part. Who does more work, or do they both do the same amounth? Who has more power? Explain.
Find the gravitational potential energy of a body of mass 25kg,kept at a height of 4m If g=10m/s'.
Answer:
Explanation:E=mgh=25×4×10=1000J
Is a football tackle an elastic or inelastic collision and why?
A: elastic, because momentum is conserved
B: inelastic, because kinetic energy is conserved
C: inelastic, because momentum is not conserved
D: inelastic, because kinetic energy is not conserved
If the kinetic energy of an object changes, then the collision is considered inelastic. This is regardless of whether the objects sticks together or not.
My best answer for this question would be D) inelastic, because kinetic energy is not conserved.
We can tell from the collision that it is not elastic.
Momentum is is conserved, it transfers to the other player.
Kinetic energy is not conserved, at it turns into internal friction.
I hope this helps! :)
A football tackle is an inelastic collision , because kinetic energy is not conserved.
What is collision?When two bodies or particles move towards enough to interact with each other it is called the particles or the bodies are colliding.
What are the types of collision?Elastic collisioninelastic collisionWhat is an elastic collision?In this type of collision , there is no loss of kinetic energy.The momentum and kinetic energy both are conserved.What is an inelastic collision?in this type of collision , there is a loss of kinetic energy.The momentum of the system is conserved but the kinetic energy is not conserved .So, when the football tackles it's kinetic energy changes.
Thus, A football tackle is an inelastic collision , because kinetic energy is not conserved.
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the schwarzschild radius of a black hole depends on
Answer:
The mass of the object.
Explanation:
Happy Thanksgiving!
The Schwarzschild radius of a black hole depends solely on its mass. The Schwarzschild radius is a concept in general relativity that defines the boundary known as the event horizon.
The formula for the Schwarzschild radius is given by:
r_s = 2GM / c²
Where: r_s is the Schwarzschild radius
As the mass of the black hole increases, its Schwarzschild radius also increases. This means that a more massive black hole has a larger event horizon and a stronger gravitational pull.
The mass of the black hole is the primary factor determining the size of the Schwarzschild radius, while other properties, such as spin or charge, can also affect the structure and behavior of the black hole but do not directly impact the Schwarzschild radius.
Therefore,The Schwarzschild radius of a black hole depends solely on its mass.
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• What net force is needed to accelerate a 1200 kg car along a
horizontal surface from rest to 130 km/h in 80 seconds?
Hi there!
We can begin by converting 130 km/h to m/s:
[tex]\frac{130km}{1hr} * \frac{1hr}{3600s} * \frac{1000m}{1km} = 36.11 m/s[/tex]
Find the acceleration associated with this velocity change in the given time frame:
vf = vi + at (vi = 0 m/s)
vf = at
vf/t = a
36.11/80 = 0.45 m/s²
Now, we can calculate Net Force using Newton's Second Law:
∑F = ma
∑F = (1200)(0.45) ≈ 540 N
A 1,000 kg truck is traveling at 3 m/s. Suddenly, the driver sees a herd of cows on the road ahead and applies the brakes. The truck's tires could fail after doing 5,000 J of work to slow the vehicle. Can the truck stop before the tires fail?
A. Yes, the total KE the tires need to transfer out of the system is less than 5,000 J.
B. Yes, the tires do not do any work, it is only the brakes that do work.
C. No, the truck had to stop suddenly and the quick change in KE will cause the tires to fail.
D. No, the total KE the tires need to transfer out of the system is more than 5,000 J.
This question involves the concepts of the law of conservation of energy and kinetic energy.
The correct option is "A. Yes, the total KE the tires need to transfer out of the system is less than 5,000 J".
According to the law of conservation of energy:
Loss in Kinetic Energy = Work done by the tires
[tex]\frac{1}{2}mv^2=W[/tex]
where,
W = work done by tires = ?
m = mass of the truck = 1000 kg
v = speed of the truck = 3 m/s
Therefore,
[tex]W=\frac{1}{2}(1000\ kg)(3\ m/s)^2[/tex]
W = 4500 J
Since the failure limit of work done by the tire is 5000 J, which is greater than the actual work done by the tire in this scenario. Hence, the tire will not fail in this case.
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The attached picture explains the law of conservation of energy.
Which of these is a unique use of beta particles?
A. CT scanners
B. Tracing chemicals in the environment C. Killing bacteria
D. Smoke detectors
Answer:
The answer is A, CT scanners.
can someone pls help me in this q
Answer: B
Explanation: