Can someone please help me with science
A 97.3 kg horizontal circular platform rotates freely with no friction about its center at an initial angular velocity of 1.67 rad/s . A monkey drops a 9.67 kg bunch of bananas vertically onto the platform. They hit the platform at 45 of its radius from the center, adhere to it there, and continue to rotate with it. Then the monkey, with a mass of 21.9 kg , drops vertically to the edge of the platform, grasps it, and continues to rotate with the platform. Find the angular velocity of the platform with its load. Model the platform as a disk of radius 1.73 m
Answer:
w = 1.14 rad / s
Explanation:
This is an angular momentum exercise. Let's define a system formed by the three bodies, the platform, the bananas and the monkey, in such a way that the torques during the collision have been internal and the angular momentum is preserved.
Initial instant. The platform alone
L₀ = I w₀
Final moment. When the bananas are on the shelf
we approximate the bananas as a point load and the distance is indicated
x = 0.45m
L_f = (m x² + I ) w₁
angular momentum is conserved
L₀ = L_f
I w₀ = (m x² + I) w₁
w₁ = [tex]\frac{I}{m x^2 + I} \ w_o[/tex]
Let's repeat for the platform with the bananas and the monkey is the one that falls for x₂ = 1.73 m
initial instant. The platform and bananas alone
L₀ = I₁ w₁
I₁ = (m x² + I)
final instant. After the crash
L_f = I w
L_f = (I₁ + M x₂²) w
the moment is preserved
L₀ = L_f
(m x² + I) w₁ = ((m x² + I) + M x₂²) w
(m x² + I) w₁ = (I + m x² + M x₂²) w
we substitute
w = [tex]\frac{m x^2 +I}{I + m x^2 + M x_2^2} \ \frac{I}{m x^2 + I} \ w_o[/tex]
w = [tex]\frac{I}{I + m x^2 + M x_2^2} \ w_o[/tex]
the moment of inertia of a circular disk is
I = ½ m_p x₂²
we substitute
w = [tex]\frac{ \frac{1}{2} m_p x_2^2 }{ \frac{1}{2} m_p x_2^2 + M x_2^2 + m x^2} \ \ w_o[/tex]
let's calculate
w =[tex]\frac{ \frac{1}{2} \ 97.3 \ 1.73^2 }{ \frac{1}{2} \ 97.3 \ 1.73^2 + 21.9 \ 1.73^2 + 9.67 \ 0.45^2 } \ \ 1.67[/tex]
w = [tex]\frac{145.60 }{145.60 \ + 65.54 \ + 1.958} \ \ 1.67[/tex]
w = 1.14 rad / s
The standard cell potential (E°cell) for the reaction below is +0.63 V. The cell potential for this reaction is __________V when the concentration of Zn2+ = 1.0 M and the
concentration of Pb2+ = 2.0 x 10-4 M.
Pb2+(aq) + Zn(s) ---> Zn2+(aq) + Pb(s)
Answer:
0.52 V
Explanation:
From Nernst equation;
Ecell =E°cell - 0.0592/n log Q
E°cell = +0.63 V
[Zn2+] =1.0 M
[Pb2+] = 2.0 x 10-4 M
n = 2
Ecell = 0.63 - 0.0592/2 log[1.0/2.0 x 10-4]
Ecell = 0.63 - 0.11
Ecell = 0.52 V
Question 20
When energy is added to a wave, how can the wave change? Select all that apply
А
The frequency can increase.
The wavelengin can inc
С
The frequency can decrease.
D
The amplitude can decrease.
E
The wavelength can decrease.
F
The amplitude can increase.
Answer:
I would say A, I hope this helped ; >
how does 3rd class lever make our work easier
Answer:
the third class lever makes our work easier as effort is located at the middle, load at first and fore is applied at the buttom. which helps in accelerating work.
hope it is helpful to you
Which actions would INCREASE the potential energy of a cup
placed on a kitchen counter? Choose all of the correct
answer(s). Oh
Answer: Fill the cup with water
Add a handle to the cup
Lift the cup over the counter.
Explanation:
The options given are:
- Slide the cup away from the edge
- Fill the cup with water
- Turn the cup upside down
- Add a handle to the cup
- Move the cup to the floor
- Lift the cup over the counter
Potential energy refers to the energy that's being stored in a particular object. The formula for potential energy is given as:
PE = mgh
where,
m = mass
g = gravitational field.
h = height
The actions that'll increase the potential energy of the cup that's placed on the kitchen counter will be:
1. Fill the cup with water - This increases the weight of the cup.
2. Add a handle to the cup - The mass is increased as well.
3. Lift the cup over the counter - The height is increased.
A ball of mass 0.5 kg is swinging at a small angle from a light string of length 0.25 m. What is the period of this pendulum? Round answer to two significant digits.
Answer: 1.0
Explanation:
not sure why but that is the correct answer
Answer:
1.0
Explanation:
Correct answer on Khan Academy
What is a magnetic disc that provides long-term storage for programs and data?
Answer:
The correct answer is: A HARD DISK
Explanation:
Magnetic Disc stores data of different types and formats that can always be edited or erased at any time. An example of a Magnetic Disc is a Hard Disk.
A hard disk is a type of magnetic storage device inside a computer that store data magnetically usually for the long-term and it could store a large volume of data, though that depends on the size, because it comes in various size. However, it generally allows stored data to be retrieved easily.
A light ray bounces off a fish in your aquarium. It travels
through the water, into the glass side of the aquarium, and
then into air. As the light from the glass hits the air, the index of
refraction for air is much
than the index of refraction
for glass which causes the light to bend toward the angle that it
entered the air.
Answer:
Correct
Explanation:
Because the light can't travel as quickly in the water as it does in the air, the light bends around the pencil, causing it to look bent in the water. Basically, the light refraction gives the pencil a slight magnifying effect, which makes the angle appear bigger than it actually is, causing the pencil to look crooked.
Answer:
Because the light can't travel as quickly in the water as it does in the air, the light bends around the pencil, causing it to look bent in the water. Basically, the light refraction gives the pencil a slight magnifying effect, which makes the angle appear bigger than it actually is, causing the pencil to look crooked.
Explanation:
in which of the following does enstein's famous equation apply?
A. a driver brings a car to a halt
B. collisions between objects
C. water falling in a waterfall
D. nuclear fission and fusion reaction
Answer:
D
Explanation:
During a science lesson on changes, Ms. Sloan's students made mixtures of sulfur (the yellow substance) and iron filings (the black substance. Ms. Sloan challenged her students to separate the two substances and one group easily completed the task by using a magnet to lift the iron filings from the mixture. Next, Ms. Sloan poured the same mixture into a test tube and heated it in the Bunsen burner flame. What was the result of heating the mixture?
Answer:
Both substance will melt and become a solution.
Explanation:
When a mixture of iron filings (black substance) and sulphur powder (yellow substance) are heated in a test tube under a bunsen burner, usually they will undergo a chemical reaction where they will melt to form a new solution of ferrous sulphide.
Thus, we can say what happens is that both substances melt to form a solution.
the instrument used in measuring the speed of wind is called
Answer:
please give me brainlist and follow
Explanation:
Anemometers
The anemometer counts the number of rotations, which is used to calculate wind speed. An anemometer is an instrument that measures wind speed and wind pressure. Anemometers are important tools for meteorologists, who study weather patterns.
7 sentences
about degradable
Answer:
Many of planet earth's water pollution crises are due to the use of items that are not degradable biologically;Her address to the United Nations said we have to return to the use of degradable materialsThey are currently producing oxo-degradable materialsSweden is the third nation to perfect and implement the total use of bio-degradable plastic bagsPepsi Cola Company was reported to have promised to discontinue the use of bottles that were not degradable biologicallyAdverse weather conditions eventually make every matter degradable. Some just take longer than otherdetergents are degradable.
Cheers
A gas has a volume of 3.00 L at 10.0 °C.
What is the temperature of the gas if it
expands to 6.00 L, assuming constant pressure?
Which of the following are NOT examples of digital information storage?
a) DVD's
b) magnetic hard drives
c) compact disks
d) vinyl records
Determine the specific heat of a certain metal if a 450 gram sample of it loses 34 500 Joules of heat as its temperature starts at 150 oC and drops to 53 oC.
Answer:
c = 0.4356 J/gK
Explanation:
Given the following data;
Mass = 450 grams
Initial temperature, T1 = 150°C
Final temperature, T2 = 53°C
Quantity of heat = 34500 Joules
To find the specific heat capacity of the metal;
Heat capacity is given by the formula;
[tex] Q = mcdt[/tex]
Where;
Q represents the heat capacity or quantity of heat.
m represents the mass of an object.
c represents the specific heat capacity of water.
dt represents the change in temperature.
dt = T2 - T1
dt = 53 - 150
dt = -97°C
Converting the temperature in Celsius to Kelvin, we have;
dt = 273 + (-97) = 176 Kelvin
Making c the subject of formula, we have;
[tex] c = \frac {Q}{mdt} [/tex]
Substituting into the equation, we have;
[tex] c = \frac {34500}{450*176} [/tex]
[tex] c = \frac {34500}{79200} [/tex]
c = 0.4356 J/gK
helpp me
An object starts from REST and ends up reaching 3500 J of Kinetic Energy. How much work was done?
As you turn on the stove, you notice that your water changes temperature from 67 degrees F to 93 degrees F. How many degrees of change is that in degrees C?
Answer:
14.44 degrees of C change
Explanation:
67 to 93 F is 26 degrees F change
C = 5/9 F
26 * 5/9 = 14.44 C change
A boy pushes his baby sister on a swing in the playground. At the top
of the baby's path, she has a potential energy of 200 J.
How much potential energy will she have at the bottom of her path?
How much kinetic energy will she have at the bottom of her path?
Answer:
* If there is no friction U = 0, K = 200 J
* If there is friction U = 0, K = 200 - W
Explanation:
For this exercise we must make an assumption.
* If there is no friction
The energy of the system is conserved therefore the energy is transformed.
The potential energy is
U = m g h
at the bottom of the road there is no height therefore
U = 0
and all the energy has been transformed into kinetic energy
K = 200 J
* If there is friction, which can come from the internal friction of the car, the friction force between the car and the floor, etc.
in this case there is a loss of energy due to the work of non-conservative forces (friction).
The potential energy at the bottom of the path is hedron because there is no height U = 0
The kinetic energy is
K = U -W
K = 200 - W
where W is the work of the friction force.
Imangine a car moving down a street. From which reference point would the street appear to be moving?
A: From the sky
B:From the street
C:From the car
D: From the sidewalk
Una mujer de masa m está parada en el borde de una mesa giratoria horizontal de momento de inercia I y radio R. La mesa al principio está en reposo y tiene libertad de moverse alrededor de un eje vertical sin fricción que pasa por su centro. La mujer empieza a caminar alrededor de la orilla en direción de las manecillas del reloj (vista desde arriba) a una velocidad constante v en relación a la Tierra.
a) En qué dirección y con qué velocidad angular gira la mesa?
b) Cuál es el trabajo efectuado por la mujer para poner en movimiento la mesa?
r
[tex]- \frac{mR^2 }{I } \ v[/tex]Answer:
a) w = - [tex]\frac{m r }{I} v[/tex] , b) W = - ½ m_woman R² (1 + m_woman R / I²) v²
Explanation:
a) To solve this exercise, let's use the conservation of angular momentum.
We define a system formed by the table and the woman, therefore the torques are internal and the moment is conserved
initial instant. Before starting to move the woman
L₀ = 0
final instant. After starting to move
L_f = I w + m v r
the moment is preserved
L₀ = L_f
0 = Iw + m v r
w = - [tex]\frac{m r }{I} v[/tex] (1)
the direction of the angular velocity is opposite to the direction of the linear velocity, that is, counterclockwise
b) for this part we use the relationship between work and kinetic energy
W = ΔK
in this case the initial speed is zero and the final speed of the table, using the relationship between linear and angular variables
v = w r
we substitute
W = 0 - ½ I_total w²
I_total = I + m_{woman} R²
W = - ½ (I + m_woman R²) ( [tex]\frac{m_{woman} R}{I} \ v[/tex]) ²
W = - ½ (m_woman² R² + m_woman³ R³ / I²) v²
W = - ½ m_woman R² (1 + m_woman R / I²) v²
Lloyd walks faster than
Ronald, with a speed of
about 0.65 m/s. The canteen
is 15 meters away from their
dassroom. How many
minutes will take her to go
to the canteen?
Answer:
Time = 2.6 minutes
Explanation:
Given the following data;
Speed = 0.65 m/s
Distance = 15 meters
To find the time to get to the canteen;
Mathematically, time is given by the formula;
Time = distance/speed
Substituting into the formula, we have;
Time = 15/0.65
Time = 23.08 seconds
To minutes = 60/23.08 = 2.6 minutes
What causes tides to occur?
The gravitational attraction between the Sun, Earth, and Moon.
The magnetic pull of the Earth's poles
The shaking of the earth during earthquakes
Seafloor spreading
Answer:
The gravitational attraction between the sun earth and moon
This is the molecule in cells that forms part of the protein.
A. rRNA
B. mRNA
C .tRNA
D. DNA
The Work-Energy Principle states that work is equal to the
change in kinetic energy. What unit measures these variables!
Answer:
the workenergy principle is measured in joules
How much force is needed to accelerate a 7.1 kg skier at 4 m/s/s?
Answer: 28.4
Explanation:
F=MA
F=(7.1)(4)
F= 28.4 N
The international space station (ISS) orbits the earth with a velocity 7.6 km/s. How much energy is required to lift a payload of 2500 kg from the surface of the earth to the ISS
Answer:
7.22×10¹⁰ J
Explanation:
From the question given above, the following data were obtained:
Velocity (v) = 7.6 Km/s
Mass (m) = 2500 kg
Energy (E) =?
Next, we shall convert 7.6 Km/s to m/s. This can be obtained as follow:
1 km/s = 10³ m/s
Therefore,
7.6 Km/s = 7.6 Km/s × 10³ m/s / 1 km/s
7.6 Km/s = 7.6×10³ m/s
Finally, we shall determine the energy required as follow:
Velocity (v) = 7.6×10³ m/s
Mass (m) = 2500 kg
Energy (E) =?
E = ½mv²
E = ½ × 2500 × (7.6×10³)²
E = 1250 × 57760000
E = 7.22×10¹⁰ J
Thus, 7.22×10¹⁰ J of energy is required.
Water in a tank which is positioned 5 feet above the ground is _____ potential energy? (answers would be like thermal, electric, mechanical)
Answer:
Mechanical
Explanation:
The tank is at rest. And energy of any substance at rest is known as potential energy.
Now, in forms of energy, potential energy is a type of mechanical energy.
Thus, the correct option is mechanical Energy.
can u get this right?
Mark the correct statement: a) Charges flow through a circuit b) voltage is applied across the circuit c) voltage is the ratio of energy per coulomb of charge d) All of the above e) none of the above
Answer:
The correct option is;
d) All of the above
Explanation:
a) In an electric circuit through which electric current flows, it is due to the electric charges which can be the negatively charged electrons or the positively charged protons
b) Voltage is the potential difference that results in current flowing through the circuit, therefore, the voltage is applied across the circuit through which current flows
c) The voltage which is the electric potential difference is the change in potential energy in joules of a given system due to the movement of a test charge (in Coulombs) between points in the electric field, ΔE, divided by the value of the test charge, 'q'
V = ΔE/q
Therefore, all of the above are correct.