Answer:
The ball is going to be spinning in a clockwise direction.
Jessica stretches her arms out 0.60 m from the center of her body while holding a 2.0 kg mass in each hand. She then spins around on an ice rink at 1.1 m/s.
a. What is the combined angular momentum of the masses?
b. If she pulls her arms into 0.15 m, what is her new linear speed?
I'm really confused ab the explanations behind this. help, please
Answer:
a.) L = 2.64 kgm^2/s
b.) V = 4.4 m/s
Explanation: Jessica stretches her arms out 0.60 m from the center of her body. This will be considered as radius.
So,
Radius r = 0.6 m
Mass M = 2 kg
Velocity V = 1.1 m/s
Angular momentum L can be expressed as;
L = MVr
Substitute all the parameters into the formula
L = 2 × 1.1 × 0.6 = 1.32kgm^2s^-1
the combined angular momentum of the masses will be 2 × 1.32 = 2.64 kgm^2s-1
b. If she pulls her arms into 0.15 m,
New radius = 0.15 m
Using the same formula again
L = 2( MVr)
2.64 = 2( 2 × V × 0.15 )
1.32 = 0.3 V
V = 1.32/0.3
V = 4.4 m/s
Her new linear speed will be 4.4 m/s
If an object absorbs energy at the same rate as it gives off energy, then __________.
Answer:
The temperature remains constant
Explanation:
From the radiation law, the net energy radiated P = Power radiated - Power absorbed
Now, let the body be at a temperature T₁ above its surroundings, the rate at which energy is given of is P₁ = σεAT₁⁴
let T₂ be the temperature of its surroundings, the rate at which energy is absorbed is P₂ = σεAT₂⁴
The net energy radiated (Power radiated) P = P₂ - P₁ = σεAT₂⁴ - σεAT₁⁴ = σεA(T₂⁴ - T₁⁴)
Now, if the object absorbs energy at the same rate it gives off energy, P₁ = P₂ and P = 0.
So, σεA(T₂⁴ - T₁⁴) = 0
Since σεA ≠ 0 then (T₂⁴ - T₁⁴) = 0 ⇒ T₂ = T₁
Since there is no temperature difference, the temperature of the object remains constant.
A ray diagram is shown what does the letter x represent?
Answer: angle of incidence
Answer:
A) angle of incidence
Explanation:
Las esferas metálicas que se muestran en la figura se cargan con 1C cada una. La balanza se equilibra al situar el contrapeso a una distancia x del eje Se pone una tercera esfera a una distancia 2d por debajo de a esfera A y cargada con -2C. Para equilibrar la balanza se debe mover el contrapeso a la derecha, porque?
Answer:
this relationship to be true the value x ’must be positive, so it must move to the right.
Explanation:
En este ejercicio debemos utilizar la relacion de equilibrio rotacional.
Fijemos un sistema de referencia situado en el eje de jiro del sistema y la rotación antihoraria es positiva.
Las esferas estan a la izquierda y el contrapeso ala derecha
W d = w_contrapeso x
donde W es el peso de las esferas de d su distancia hasta eleje de giro
Ahora colocamos la carga negativa debajo de la esfera A, como las cargas son de diferente signo las dos esferas se atraen, lo que crea una fuerza hacia bajos de magnitud
F =k q₁ q₂/r²
F =8,9 10⁹ 1 2/ (2d)²
F = 4,45/d² N
volvamos escribir la ecuación de equilibrio rotacional con esta fuerza
F d + W d = W_contrapeso (x+x’)
(4,45 10⁹ /d²) d + W d = W_conrapeso x+ W contrapesos x’
en la primera ecuación vimos que dos terminos se igualan ,por lo cual se anulan quedando
4,45 10⁹/d = W contrapeso x’
para que esta relación sea cierta el valor e x’ debe ser positivo, por lo cual debe moverse a la derecha.
Traduction
In this exercise we must use the relationship of rotational equilibrium.
Let's fix a frame of reference located on the system's axis of rotation and the counterclockwise rotation is positive.
The spheres are on the left and the counterweight on the right
W d = w_counterweight x
where W is the weight of the spheres of d its distance to the turning axis
Now we place the negative charge under sphere A, as the charges are of different sign the two spheres attract, which creates a downward force of magnitude
F = k q₁ q₂ / r²
F = 8.9 10⁹ 1 2 / (2d)²
F = 4.45 / d² N
let's rewrite the rotational equilibrium equation with this force
F d + W d = W_ counterweight (x + x ’)
(4.45 10⁹ / d²) d + W d = W_counterweight x + W counterweights x’
In the first equation we saw that two tenunos are equal, which is why they cancel, leaving
4.45 10⁹ / d = W counterweight x ’
for this relationship to be true the value x ’must be positive, so it must move to the right.
You have a graduated cylinder that you use to measure volume. The cylinder
is marked in 1 ml increments. Which measurement made using this cylinder
contains the correct number of significant digits?
A. 35.5 ml
B. 320.01 ml
C. 75.333 ml
D. 21 ml
Answer:
35.5 ml
Explanation:
The other guy made me get the question wrong lol here ya go good luck
HELLLP PLEASE || the graph below shows a conversion of energy for a skydive jumping out of a plane and landing safely on the ground. which energy is represented by line A? A) Potential B) Thermal C) Kinetic D) Total Energy
Answer: I maybe wrong but i'm pretty sure its C) Kinetic energy
e)
The surface area of foot of Bimaba is 150cm? If she weighs 50kg,
how much pressure does she exert on the ground, as she stands on
her one foot? (32666.67 pa)
Answer:
Pressure, P = 32666.66 Pa
Explanation:
It is given that,
Surface area of foot of Bimaba is 150 cm² or 0.015 m².
Her weight is 50 kg
We need to find the pressure does she exert on the ground, as she stands on her one foot. The force acting per unit area is called pressure. It can be given by :
[tex]P=\dfrac{F}{A}\\\\P=\dfrac{mg}{A}\\\\P=\dfrac{50\times 9.8}{0.015}\\\\P=32666.66\ Pa[/tex]
So, the pressure is 32666.66 Pa.
a loop with a break in it that prevents current form flowing is called a(n) blank circuit
Answer: it is called a open circuit
Explanation:
A 4400 W motor is used to do work. If the motor is used for 200 s, how much work could it do? (Power: P = W/t) 22 J 4200 J 4600 J 880,000 J
Answer:
880,000 J
Explanation:
P = W/t
4400 W = W / 200 s
W = 880,000 J
Answer:
880,000 J
Explanation:
Which of the following statements DOES NOT explicitly describe a transfer of energy,
A. A ball dropped from a height hits the ground with a high speed.
B. The collisions produced in a nuclear reaction heat up the surroundings.
C. A plane increases its air speed from 150 mi/hr to 200 mi/hr.
D.The electricity from the power socket causes the fan to turn
Answer:
Option A
Explanation:
A. A ball is dropped from a height and hits the ground with a high speed. As this is a ball, it has elastic energy, so upon impact on the ground the kinetic energy can 1. go into making sound upon impact, or 2. go into making the ball bounce upward again. There may by more possible energy transfers, but this is what should occur in like conditions. Now it didn't mention that the ball transfers energy as such, only that the ball hits the ground at high speed. Thus, this statement does not explicitly describe a transfer of energy.
_______________________________________________________
Just to confirm that this is the correct answer, take a look at the other options. Option B states that the energy from the collision is transferred to heat, not in those exact words but still is given. Option C states that the plane increases speed, most likely transferring energy to the atmosphere, in the form sound. In option d the electricity causes the fan to turn, an explicit statement of the transfer of energy.
Hope that helps!
Place the types of radiation in order of INCREASING mass.
Answer & explanation:
Gamma Radiation (γ): Also called gamma rays. Gamma radiation is made of electromagnetic waves, has zero charge and mass, continuously emits heat and has the ability to ionize air and make it conductive of electric current. Beta radiation (β): Beta rays or beta particles, are electrons, negative particles with charge - 1 and mass number 0.Alpha radiation (α): Also called alpha particles or alpha rays, are particles charged by two protons and two neutrons. They have positive charge +2 and mass number 4.A diverging lens of focal length 18.0m is used to view a shark that is 90.0m away from the lens. If the image formed is 1.0m long, calculate the: (i) image distance; (ii) length of the shark.
Answer:
i. + 22.5 m ii. 4.0 m
Explanation:
i. Image distance
Using the lens formula
1/u + 1/v = 1/f where f = focal length = + 18.0 m, u = object distance = distance of shark away from lens = + 90.0 m and v = image distance from lens = unknown
So, we find v
1/v = 1/f - 1/u
= 1/+18 - 1/+90
= (5 - 1)/90
= 4/90
v = 90/4
= + 22.5 m
So the image is real and formed 22.5 m away on the other side of the lens.
ii Length of Shark
Using the magnification formula, m = image height/object height = image distance/object distance. image height = 1.0 m where object height = length of shark.
m = image distance/object distance
= v/u
= +22.5/+90
= 0.25
0.25 = image height/object height
So,
object height = image height/0.25
= 1.0 m/0.25
= 4.0 m
So, the length of the shark is 4.0 m
Calculate the volume of the part of the sphere that will be immersed in the mercury when the density of the sphere is 7800kg/metre cubic and volume of 136centrimetre cubic and the density of the mercury is 13600kg/metre cubic
Answer:
78 cm³
Explanation:
The Volume Immersed = (density of object/ density of fluid) x Volume of Object
Vi = (7800/13600) x 136 = 78 cm³
What happens to the Kinetic Energy of an object if its mass stays the same but its speed is doubled
Answer:
kinetic energy is proportional to the velocity squared, increases in velocity will have an exponentially greater effect on translational kinetic energy. Doubling the mass of an object will only double its kinetic energy, but doubling the velocity of the object will quadruple its velocity.
pls mark as branliest
3.-¿ Como actuarias tú, si en pleno juego el árbitro toma una decisión, apesar de estar equivocado?¿finalizado el encuentro te despedirias del arbitro? Si - No ¿Porqué?
Answer:
Comprobar explicación
Explanation:
Si el árbitro toma una decisión en el medio del juego, a pesar de estar equivocado, normalmente, como humano, las emociones están destinadas a superarlo, pero de acuerdo con el reglamento, hay conductas aceptables y una protesta llena de emociones. en el árbitro puede salirse de las manos y conducir a más castigos de acuerdo con los libros de reglas.
Después del partido, por lo general, aún me despediría y expresaría mi desagrado tan cortésmente como pueda, pero porque cuando uno se equivoca, las emociones que lo acompañan pueden volverse increíblemente incontrolables, por lo tanto, es mejor mantener el control y no obtener castigado aún más.
¡¡¡Espero que esto ayude!!!
A right triangle ABC has sides /AB/ =9cm, /BC/=12cm find /AC/ and angles ACB and ABC if angle BAC= 90°
fdi9bn 08989089089008i uuuuuuri9ij
Find the average velocity if the takeoff velocity of an airplane on a runway is 300 km/hr with an acceleration of 1 m/s2 . A) 30 sec B) 41.7 sec C) 72.2 sec D) 83.33 sec
Answer:
83.33s
Explanation:
velocity=300km/hr ,acceleration =1m/s2
But before we can make this calculation,we have to make sure that both the acceleration and velocity are in the same units.So I decided to Chang the velocity to m/s.
Converting 300km/hr into m/s;
Changing 300km into m=300000m
Changing 1hr into secs=3600sec
Velocity in m/s=83.33m/s
But Time =velocity/acceleration
=83.33/1
=83.33sec
You have to decide what you want. Your question says "Find the average velocity", but the choices you listed are all times, not velocities.
(300 km/hr) x (1 hr / 3600 sec) = 83.33 meters/sec
-- If the airplane starts from rest and accelerates uniformly at 1 m/s², it'll take 83.33 seconds to reach takeoff speed.
-- If it starts from rest and accelerates uniformly to 83.33 m/s, then its average speed is 41.67 m/s no matter what its acceleration may be.
Resistance and resistivity are related by a: 1.factor that is dependent on the length of the material 2.factor that is dependent on the area of the material 3.proportionality constant dependent on the identity of the material 4.proportionality constant dependent on the source of the material
Answer:
1. factor that is dependent on the length of the material.
2. factor that is dependent on the area of the material
Explanation:
Resistance R is directly proportional to its length L of an object and it is inversely proportional to the crossectional area of that object.
Mathematically, this is represented as:
a) Resistance R is directly proportional to its length L of an object
R ∝ L ......... Equation 1
b) Resistance R is inversely proportional to the crossectional area (A) of an object
R ∝ 1/A ............ Equation 2
Combining the two equations together, we have:
Resistance R is directly proportional to its length L of an object
R ∝ L/A .......... Equation 3
Resistivity of a material is the natural or inherent or intrinsic property that a material has. The Resistivity of a material is not dependent on the length or crossectional area of such material. It is only temperature dependent.
The resistance of a material is also dependent on the resistivity of the material. This means the resistance of a material is directly proportional to the resistivity of the material.
R ∝ ρ........Equation 4
Combining Equation 4 and 3 together, we have:
R = ρL/A
Where:
R = Resistance
ρ = Resistivity
L = Length of the material
A = Crossectional area of the material
Resistance and resistivity are related by a factor that is dependent on the length of the material a factor that is dependent on the area of the material
A gas baloon bursts when comes to a high altitude.... Plss answer it
Answer:yess
Explanation:as weather balloons travels from the earth's surface, the air pressure around ballons decreases slowly.As the air gets thinner,the gallons casing gets tighter.
This is due to gas expanding within balloon.The expanding gas causes the balloons to reach maximum height and it burst.
A boy throws a baseball onto a roof and it rolls back down and off the roof with a speed of 3.80 m/s. If the roof is pitched at 38.0° below the horizon and the roof edge is 3.30 m above the ground, find the time the baseball spends in the air and the horizontal distance from the roof edge to the point where the baseball lands on the ground. HINT
Answer:
a) The baseball spends 0.674 seconds in the air
b) The horizontal distance from the roof edge to the point where the baseball lands on the ground = 2.02 m
Explanation:
The ball's initial speed, u = 3.8 m/s
θ = 38°
The edge of the roof has a height, H = 3.30 m
The vertical motion of the baseball can be given by the equation:
[tex]H = U_{y} t + 0.5a_{y} t^{2}[/tex].........(1)
Vertical acceleration of the baseball, [tex]a_y = 9.8 m/s^2[/tex]
The vertical component of the initial speed can be calculated by:
[tex]U_y = Usin \theta\\U_y = 3.8 sin 38\\U_y = 2.34 m/s[/tex]
Substituting the appropriate values into equation (1):
[tex]3.8 = 2.34 t + 0.5(9.8)} t^{2}\\4.9t^2 + 2.34t - 3.8 = 0[/tex]
Solving for t in the quadratic equation above:
t = 0.674 s
To calculate the horizontal distance, S, use the formula below:
[tex]S = U_xt + 0.5a_xt^2[/tex]
Horizontal acceleration of the baseball, [tex]a_x = 0 m/s^2[/tex]
The horizontal component of the initial speed can be calculated as:
[tex]U_x = Ucos \theta\\U_x = 3.8 cos 38\\ U_x = 2.99 m/s[/tex]
S = 2.99(0.674) + 0.5(0)
S = 2.02 m
Which property of sugar makes it different from white crystalline sand?
Answer:
The property of sugar which makes it different from sand is that sugar can dissolve in water. Explanation: however the power of dissolving of sand is not present. This is due to the presence of interaction between sugar and water.
Explanation:
I hope that was useful
What type of bond is most likely to form between atoms of the same element when the element is a metal?
Answer:Covalent bond
Explanation:
a solid weighs 18.36N on the surface of the moon. The force of gravity on the moon is 1.7Nkg-1. Determine the mass of the solid
Answer:
mass of the solid is 10.8kg
Explanation:
Weight of the solid=w=18.36N
Force of gravity on the surface of the moon=g=1.71Nkg^-1
Mass of the solid on the moon=m=?
as we know that
weight=mass×force of gravity
here we have to find the mass
[tex]\frac{weight}{force of gravity}[/tex]=mass
mass=[tex]\frac{18.36N}{1.7Nkg^-1}[/tex]
Mass of the solid=10.8kg
i hope it will help you
A ball is thrown at a wall with a velocity of 5 m/s and bounces off at 4 m/s as shown in the diagram. If the impulse provided by the wall is 3 Nm, then what is the mass of the ball?
Answer:
m = 3 kg
Explanation:
It is given that,
Initial speed of a ball is 5 m/s, u = 5 m/s
Final speed of a ball is 4 m/s, v = 4 m/s (as it bounces)
Impulse provided by the wall is -3 N-m (impulse is provided in opposite direction)
We need to find the mass of the ball. Impulse provided to an object is given by the change in its momentum as :
J = m(v-u)
m is mass of the ball
[tex]m=\dfrac{J}{(v-u)}\\\\m=\dfrac{-3}{(4-5)} \\\\m=3\ kg[/tex]
So, the mass of the ball is 3 kg.
The coldest layer of Earth’s atmosphere is the __________. a. troposphere c. mesosphere b. stratosphere d. thermosphere
Answer: c.mesosphere
Explanation: Temperatures can reach lows of -90 degrees Celsius in the mesosphere, making it the coldest layer of the earth's atmosphere. The mesosphere extends above the stratosphere and ranges from 50 km to 87 km above the surface.
What kind of force are you using when you squish a marshmallow?
Answer:
Compression
Explanation:
I would think it would be compression because you are compressing the marshmallow, and pushing it down until its compact.
Answer: Compression, I to had to get an answer for this but imma help you out :)
Which is an example of a fission reaction? Check all that apply.
H + H → He 2n
+
239 Pu + n + 1904 Ce + Kr + 2n
295 Am + in → 154 La + 95 Sr + 3 in
13C + H + 4N
Answer:
Check Explanation
The fission reactions include
239 Pu + n → Ce + Kr + 2n
And
295 Am + in → 154 La + 95 Sr + 3 n
Explanation:
A fission reaction is a radioactive reaction in which an atom with a heavy nuclei splits into atoms with smaller or lighter nuclei usually brought about by the attack of a fundamental particle and accompanied by the release of some fundamental particles (neutrons mostly) and energy.
Although, the reactions to be examined aren't totally clear, we can still guess which element is which and know which of the reactions has a heavier nuclei splitting into smaller ones.
1) H + H → He + 2n
Two hydrogen atoms combine to give an helium atom and release neutrons too, showing that here, smaller molecules combine to form a bigger one. Hence, this isn't a fission reaction, rather, it's a fusion reaction.
2) 239 Pu + n → Ce + Kr + 2n
Here, Pu (Plutonium, atomic mass 239), a heavy nuclei that splits into smaller nuclei, Ce (Cerium, atomic mass 140) and Kr (Krypton, atomic mass 84) together with some neutrons to fit the definition of a fission reaction. Hence, this reaction is a fission reaction.
3) 295 Am + n → 154 La + 95 Sr + 3 n
Here, Pu (Americium, atomic mass 295), a heavy nuclei that splits into smaller nuclei, Ce (Lamthanium, atomic mass 154) and Sr (Strontium, atomic mass 95) together with some neutrons to fit the definition of a fission reaction. Hence, this reaction is a fission reaction.
4) 13C + H → 14N
Carbon 13 combines with a hydrogen element to mutate and give nitrogen-14, a heavier nuclei, showing all signs of a nuclear fission and not fission.
Hope this Helps!!!
Answer:
b and c
Explanation:
got it correct on edg
I NEED HELP PLEASE, THANKS! :) Why is it a good idea to touch a metal pole, or similar conductor, before filling up a car with gas?
Answer:
While filling up the gas, a static discharge can take place which is really dangerous for us. It can even ignite a fire at the gas station. Touching the metal pole or any conductor will pass all of the charge into the Earth and thus we'll keep safe.
Answer:
It is a good idea to touch a metal pole or similar conductor before filling up a car with gas because it will discharge any static electricity on you, making it safer for everyone.
Explanation:
when a scientist is conducting research about all the plants and wildlife in the Mojave desert as well as the deserts resource such as water and soil the scientist is studying
Answer:
The correct answer to the following question will be "An ecosystem".
Explanation:
The environment seems to be all the species of animals and plants that people living in a defined place, including the complex nature of relationships between them because of environmental surroundings.Sometimes whenever a scientist seems to be doing work on both animals and plants throughout the desert, including on wilderness freshwater resources as well as soil.So that the above seems to be the right answer.
I NEED HELP PLEASE, THANKS :) What does it mean when white light is diffracted and at a particular location the color seen is blue?
Answer:
This is because white light consists of 7 colours with different angles o deviation or retraction.
Explanation:
When a narrow beam of light is refracted by a prism the light spreads into a band of colours (called the spectrum of light )
But in this case if a blue colour is observed it is due to the angle of refraction ,for instance red is refracted the least and hence is seen
Answer:
When while light is diffracted and at a particular location blue color is seen, this means that blue color is reflected while all other colors will be absorbed. When the blue color is seen denotes the shortest wavelength being reflected and all other being absorbed at the specified location.