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.
Which state of matter has molecules that barely move at all?
liquid
gas
solid
They are all the same.
Answer:
the answer is solid.
Explanation:
solid particles have a definite volume and shape therefore they cannot move are they are whole. the particles of solid are closely packed together, barely move, and barely vibrate.
d) A 2-kg book is held 1 m above the floor is for 10s. The work done on the book is zero and its potential energy is 20 J. Is it true or false?
Which is required for
conduction?
A.moving fluids
B. Two substances in direct
contact with one another
C. Two substances in close proximity, but not necessarily touching
Answer:
You need (B) Two substances in direct contact with one another to have conduction.
I hope this helped at all.
1 point
A roller coaster is 20 m high and traveling 11 m/s. If the roller coaster has a
mass of 150 kg, what is its total energy? (only put the number, no units or
commas)
Answer:
ETotal=38505J
Explanation:
Known values:
m=150kg
h=20m
v=11m/s
KE=mv^2/2
PE=mgh
ETotal=PE+KE
KE=(150(11^2))/2
KE=9075
PE=150(9.81)(20)
PE=29430
ETotal=9075+29430
ETotal=38505J
You increase your walking speed from 1 m/s to 3 m/s in a period of 1 s.
What is your acceleration?
5 m/s2
3 m/s2
2 m/s2
4 m/s2
Answer:
2 m/s2
Explanation:
|acceleration| = (change in speed) divided by (time for the change)
Change in speed = (end speed) minus (start speed)
Initial speed of walking = 1 m/s
Final speed of walking = 3 m/s
Change of speed in walking = (3 - 1) m/s
= 2 m/s
Time in which the change of speed occurred = 1 sec
Then
Acceleration = Change of Speed/ Time taken
= 2/1 m/s^2
= 2 m/s^2
Therefore the answer is 2 m/s2.
The acceleration is 2 m/s².
What is acceleration?Acceleration can be defined as the rate of change of velocity.
The acceleration can be calculated using the formula below.
Formula:
a = (v-u)/t................... Equation 1Where:
a = accelerationv = Final velocityu = Initial velocityt = time.From the question,
Given:
v = 3 m/su = 1 m/st = 1 secondsSubstitute these values into equation 1
a = (3-1)/1a = 2 m/s².Hence, The acceleration is 2 m/s².
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8.
Linda thinks that her home is dirty and she will become
contaminated if she does not clean her kitchen. This daily cleaning takes hours to complete. Her hands
are rubbed raw, she has not been able to maintain friendships, and she is struggling to keep up with
work.
Answer:
she just have to maintain her daily work routin to kepp up with work .she can use glovs than her hand will be protected .and for mantain friendship she have to franky with other and allways talk to you'r friends no matter how bg you are talking with friends can be verry helpfull
How can speed be defined
A) acceleration
B) change in velocity/time
C) distance / time
D) displacement/time
Answer:
Speed can be defined in (C) distance / time.
I hope this helped at all.
A system releases 622 kJ of heat and does 105 kJ of work on the surroundings. What is the change in internal energy of the system
Answer:
Δ-727 or -7.27x10²kJ
Explanation:
ΔV=q-w
(q)= -622
(w)= -105
(both negative because it indicate loss of energy)
ΔV= -622+(-105)
ΔV= -727 kJ
The change in internal energy of the system when it released a heat of 622 kJ and does a work of 105 kJ on the surroundings is -727 kJ.
What is change in internal energy?Internal energy is all the energy contained in an object.
To calculate the change in internal energy of the system, we use the formula below.
Formula:
ΔU = Q-W............. Equation 1Where:
ΔU = Change in internal energy of the system,W = work done by the systemQ = Heat released by the system.From the question,
Given:
Q = - 622 kJ ( released of heat)W = 105 kJ.Substitute these values into equation 1
ΔU = -622-105ΔU = -727 kJHence, the change in internal energy of the system when it released a heat of 622 kJ and does a work of 105 kJ on the surroundings is -727 kJ.
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PLS ANSWER FAST CORRECT ANSWER WILL BE BRAINLIEST
Answer:
Current
Explanation:
i have science map and i dont know what ro answer please help me asap
Answer:
C
Explanation:
The correct answer is C because it puts equivalent measurements in the equivalent cup size. Both cups in answer C are the same measurement: 200 mL. The water in both cups is also the same measurement: 100 mL of 70 degrees Celsius. This is important because equivalent measurements for everything mean the experiment will be fair, equal, and accurate. If the measurements were not equal to each other, your experiment would not be as accurate.
A plane flying above the ground has 60,000 joules of kinetic energy and 6,000 joules off gravitational potential energy. How much mechanical energy does the plane have?
Answer:
66,000J
Explanation:
Mechanical energy = Gravitational energy + Kinetic Energy
ME = 6,000 + 60,000 = 66000 J
What role does physical health play into nutrition?
A 3.00 kg toy falls from a height of 10.0 m. Just before hitting the ground, what will its kinetic energy be? (Disregard air resistance; g = 9.81 m/s2.)
The kinetic energy of the toy before hitting the ground is 294.3 J
From the question given above, the following data were obtained:
Mass (m) = 3 Kg
Height (h) = 10 m
Acceleration due to gravity (g) = 9.81 m/s²
Kinetic energy (KE) =?Before the toy will hit the ground, the potential and kinetic energy of the toy will be the same.
KE = PE = mgh
KE = 3 × 9.81 × 10
KE = 294.3 JTherefore, the kinetic energy of the toy is 294.3 J
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A concave mirror has a centre of curvature of 24.0 cm. An object 2.5 cm tall is placed 40.0 cm in front of the mirror.
a) At what distance from the mirror will the image be formed?
b) What is the height of the image?
Answer:
Object distance should be 48
Explanation:
in pic
_____________________________
(hope this helps can I pls have brainlist (crown)☺️)
Seismic waves do not travel along the Earth’s surface.
Please select the best answer from the choices provided
T (true)
F (false)
Both choices are correct.
Some seismic waves travel along the Earth's surface.
Others don't.
Answer:
False
Explanation:
Edge2022
A student jumps off a sled toward the west after it stops at the bottom of an icy hill.
Based on the law of action-reaction, in what direction will the sled most likely move as the student jumps off?
Answer:
Explanation:
That’s dangerous who would do that.
Me
This Constitutional right forbids Congress from sending a person to prison__
Explain what this Constitutional right is:___
The formation and operation of prisons, as well as inmates' rights, are governed by federal and state regulations. Although prisoners may not have full constitutional rights, the Eighth Amendment's restriction on cruel and unusual punishment protects them.
please help me solve this and give an explanation
Answer:
6.5
Explanation:
Because 1.5+5=6.5
13. A ball is dropped. According to Newton's Third Law, the action force is the
earth pulling the ball, and the reaction is:
Answer:
the ground when the ball hits it
Explanation:
A ball falls freely towards the Earth. If the action force is the Earth pulling down on the ball, then identify which of the following best describe the reaction force:
What are some simple machines that decrease mechanical advantage used to do? increase work decrease work multiply distance to increase speed.
Answer:
Wheel and axleForce multipliersLeverInclined planePulleyScrewWedgeExplanation:
Simple machines are devices with no, or very few, moving parts that make work easier. Many of today's complex tools are just combinations or more complicated forms of the six simple machines, according to the University of Colorado at Boulder. For instance, we might attach a long handle to a shaft to make a windlass, or use a block and tackle to pull a load up a ramp. While these machines may seem simple, they continue to provide us with the means to do many things that we could never do without them.
Have a great day! :D
Some machines decrease mechanical advantage and are utilized to multiply distance to decrease speed.
What is the mechanical advantage?Mechanical advantage can be described as a measure of the ratio of output force to input force in a system. Mechanical advantage is used to analyze the forces in simple machines such as levers and pulleys.
Mechanical Advantage= output force (load) /input force(effort)
The mechanical advantage will increase as the slope of the inclined plane decreases but the load has to move with more distance. Under the mechanical advantage, the distance the load will move will be a fraction of the distance through applied force.
Thus, the mechanical advantage is decreased by some simple Machines decrease and are used to multiply distance to decrease speed.
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#SPJ2
Density of water is-
Answer:
The density of water is around 997 kg/m³ of 1 gran per millilimeter
An amateur astronomer has just discovered a dwarf planet in an orbit past Pluto. Choose the best unit of measure to describe how far out in the solar system it is from the Sun.
Mercury’s natural state is where the atoms are close to each other but are still free to pass by each other. In which state(s) could mercury naturally exist?
Answer:
Mercury's natural state is where the atoms are close to each other but are still free to pass by each other. In which state(s) could mercury naturally exist?
Liquid is the answer
Explanation:
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.
Managers use information systems to help them make decisions that will improve their businesses. What three levels of information do managers need to make these decisions? Provide one example of how information systems can provide this data.
The main categories of information systems include management-level system, operational-level system, and strategic-level system.
Information system simply means the integrated set of components that are vital for the collection, storage, and processing of data to make organizational decisions.
Information systems can be used at operational level in order to provide data that can support operational activities by keeping track of the transactions of the company.
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I need to know how to draw the diagram of the last two questions
Answer
In the parallel circuit, you have to position the switch on only one of the loops.
ASAP
A truck is speeding up (with a constant acceleration) from rest to 45 m/s and it takes it 15 seconds to do so. How far will the car travel?
Answer:
675 KM
Explanation:
hAVE A NICE DAY
Một oto đang chuyển động thẳng đều với vận tốc 36km/h thì hãm phanh sau 20s thì ô tô dừng lại quãng đường oto đi được là
A camper stands in a valley between two parallel cliff walls. He claps his hands and notices that the echo from the nearby wall returns 0.9 s later while the echo from the farther wall returns 1.10 s later. If the air temperature is -10 C, how wide is the valley?
why does the energy of characteristic x rays tend to increase for heavier elements?
The energy of characteristic x rays tend to increase for heavier elements
because the charge of the nucleus increases.
X ray is a form of an electromagnetic spectrum and the energy is directly
proportional to the charge of the nucleus. This implies that an increase in
the nucleus charge will lead to a corresponding increase in x ray energy
and vice versa.
X rays energy is also usually more in heavier elements than when
compared to lighter elements
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