The kinetic energy of a javelin is 81 J, and its speed is 9.0 m/s. What is its mass?

A. 0.5 kg

B. 1.0 kg

C. 2.0 kg

D. 9.0 kg

Answers

Answer 1

Answer:

2 kg

Explanation:

K.E. = 1/2 m v^2

81   = 1/2  m (9^2)

1 = 1/2 m

m = 2 kg


Related Questions

PLEASE HELP ASAP
1) During a transformation, a positive radon nucleus repels a positive helium nucleus
(m = 6.64 × 10–27 kg), giving it an energy of 7.37 × 10–13 J. How fast is the helium
nucleus moving when it is far away from the radon nucleus? Draw an energy bar chart
to assist you.

2) A positive charge of +7.2 μC and a positive charge of +6.64 μC are 10 cm apart, at
rest. After t seconds, the particles are at a distance 15 meters apart with velocities
–8.7 m/s and 9.1 m/s, respectively. Draw an energy bar chart of the situation and
determine the direction of the forces and velocities of each charge.

Answers

I dotn know the first question but the second one. If u think about it positive charge is +7.2 so then add +6.64 then get the answer to that then u, know there are 60 seconds in a miniute and

i need help, please. ASAP!!!!

Answers

Answer: A

Explanation:

Work is defined as the inner product between the force vector and the distance traveled. Due to the energy-work theorem, the total work done is equal to the change in kinetic energy. But since there is friction, we must also take into account that frictional force. The frictional force opposes the motion of the object, and will take away energy from the object in the form of heat. Therefore, we must subtract the amount of energy done by friction from the total kinetic energy.

For your case, the answer would be A. Although, that is technically incorrect. The car does not gain energy due to friction.

Which of these circuits has a voltmeter?
O
(A)
(B)
(C)
(D)
(E)
ОА А
OBB
Ос. с
ODD
О Е Е

Answers

Answer:

I think is o or mavey it could be D

Why does a magnet exert force on another magnet when the two magnets are not in contact?

Answers

Answer:

1. Why does a magnet exert force on another magnet when the two magnets are not in contact? The magnetic field from north to south increases when they're closer together, and when they repel the repelling force increases as well. This is all due to the magnetic field.

Correct me if I'm wrong, Hope this helps

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On the electromagnetic spectrum, what type of light is higher energy: X-rays or radio waves?

Answers

Answer:

Radio

Explanation:

X-rays is 10 x 10^-10

radio is 10⁴

25 cm 40° 35 N

what's the torque? ​

Answers

Answer:

t = 562.44 Newton centimeters

or

t = 5.62 Newton meters

Explanation:

The eqaution for torque is:

t = rFsin(θ)

We are given r, f, and θ.

Fill in what we know.

t = 25*35*sin(40)

t = 562.44

t = 562.44 Newton centimeters

or

t = 5.62 Newton meters

What does it mean for something to have charge?

Answers

the property of matter that is responsible for electrical phenomena, existing in a positive or negative form.
When talking about charge, it is usually referring to an electric charge. A charge can be positive or negative.

Two pistons are in an enclosed volume with fluid in between them, such that
movement in one piston affects the location of the other piston, as shown in
the image below. If an explosion occurs in the piston on the left such that it
moves 1 m, what is the distance that the piston on the right will move
(assuming that friction can be neglected)? (Recall that work on an object is
equal to the force on the object times the distance it is moved, and that work
is conserved.)
Cross-sectional area - 25 mm
Cross-sectional area = 0,5 m
A. 2 m
B. 0.5 m
C. 1 m
D. 0.25 m

Answers

Answer:

The pressure in the fluid just below Piston 1 is

p_1=F_1/A_1=361\text{ Pa}.p

1

=F

1

/A

1

=361 Pa.

The pressure in the fluid just below Piston 2 is the same according to Pascal's law:

p_2=p_1=361\text{ Pa}.p

2

=p

1

=361 Pa.

The force being exerted on Piston 2 to keep the two pistons in equilibrium is

F_2=p_2A_2=330\text{ N}.F

2

=p

2

A

2

=330 N.

Explanation:

what is this one too i dont know im lazy right now

Answers

Answer:

The answer is Digestion (d)

A car is traveling in a race. The car went from the initial velocity of 35 m/s to the final velocity of 65 m/s in 5 seconds
What is the acceleration?
- 13 m/s
om/
6 m/s
13 m/s

Answers

Answer:

6m/s

Explanation:

a = (v-u)/t

acceleration, a

initial velocity, u

final velocity, v

time, t

substitute values and you'll get the answer

Answer:

6 m/s

Explanation:

Which force counteracts motion whenever two surfaces come into contact?.

Answers

Answer:

crush

Explanation:

because the body come into contact

Do tuning forks make sounds when hit from the vibrations? I'll give brainiest

Answers

Answer:

Yes

Explanation:

they make sound due to the fact that the vibration from the tuning fork itself interacts with the air around it. it's also worth mentioning that anything that vibrates creates sound waves as well.

Why is a 1 solar-mass red giant more luminous than a 1 solar-mass main sequence star?.

Answers

Answer:

No

Explanation:

I dont know please help

A sound wave passes from air into water and then into steel. With each change in medium, what happens to the speed of the wave?.

Answers

Answer:

Explanation:

You need to consider the index of refraction.

index of refraction of air: 1.00

index of refraction of water: 1.33

Index of refraction of steel: 2.75681

If the sound wave passed from air into water, it passes from a lower index to a higher index of refraction.

As the wave travels into the more dense medium (higher n), it slows down. Therefore from air to water (lower to higher) it slows down, and from water to steel (n of steel is higher that n of water) therefore it slows down even more.

A distant star gives off a visible range of light whose color depends on its temperature. Which model of light does this example support? O A. The interference model B. The particle model O C. The diffraction model OD. The wave model​

Answers

The statement 'a distant star gives off a visible range of light whose color depends on its temperature' is supported by the wave model​.

What is wavelength?

The wavelength can be defined as the periodic distance of a given wave that repeats in a constant way.

The emissivity of particles is a function of both wavelength and temperature of a given material/object. Visible wavelengths range from 700 nm to 400 nm (violet color).

Star temperature largely determines its color, blue stars are warmer than yellow and red stars, and red stars are cooler than yellow stars.

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A thin uniform disk of mass m and radius r has a string wrapped

Answers

The magnitude of the weight of the disk is greater than the magnitude of the tension force of the string. ((c) [tex]F_{T} < F_{g}[/tex])

How to analysis a rigid body on dynamical condition

A rigid body is a system whose geometry cannot be neglected and in which deformations due to external forces applied on the system are negligible.

In this question we need to establish a free body diagram with all critical forces and motion conditions. There are two external forces: (i) tension ([tex]F_{T}[/tex]), (ii) weight ([tex]F_{g}[/tex]), both in newtons.

The disk falls due to gravity and rotates around the string in a case of rolling, which combines rotation and translation. By Newton's laws of motion we have the following expression:

[tex]\sum F = -F_{g}+F_{T} = -m\cdot R\cdot \alpha[/tex]   (1)

Where:

[tex]m[/tex] - Mass of the disk, in kilograms.[tex]\alpha[/tex] - Angular acceleration, in radians per square second.

By algebra we derive the following relationship between the two forces:

[tex]-F_{g} = -F_{T}-m\cdot R\cdot \alpha[/tex]

[tex]F_{g} > F_{T}[/tex]

Therefore, the magnitude of the weight of the disk is greater than the magnitude of the tension force of the string. ((c) [tex]F_{T} < F_{g}[/tex]) [tex]\blacksquare[/tex]

Remark

The statement is incomplete and poorly formatted. Correct and complete form is shown below:

A thin uniform disk of mass m and radius r has a string wrapped around its edge and attached to the ceiling. The bottom of the disk is at height 3R above the floor, as shown above. The disk is released from rest. The rotational inertia of a disk around its center is [tex]I = \frac{1}{2}\cdot M\cdot R^{2}[/tex].

When released from rest, the disk falls and the string unwinds. The force that the string exerts on the disk is [tex]F_{T}[/tex], and the gravitational force exerted on the disk is [tex]F_{g}[/tex]. Which of the following expression correctly relates [tex]F_{T}[/tex] and [tex]F_{g}[/tex] as the disk falls?

(a) [tex]F_{T} > F_{g}[/tex], (b) [tex]F_{T} = F_{g}[/tex], (c) [tex]F_{T} < F_{g}[/tex]

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An empty corn silo in the shape of a cylinder is being filled with corn

Answers

The percent of the silo filled with corn at 10 hours is 90.98%.

What is silo?

Silos are used in order to maximize the grain storage life and preserve them. They are round and tall towers with high capacity for commercial or industrial purposes.  

As the silo is in shape of cylinder, volume of the cylinder is

V = πr²h

where r = d/2 = 19/2 =9.5 ft

and h = 32 ft

Substitute the values, we get the volume of silo,

V = 3.14 x (9.5)² x 32 = 9068.32 ft³

The silo is filled with the constant rate. After 10 hours, in silo, the amount of corn will be gone doubled as compared to that of in 5 hours.

Amount of corn after 10 hours = 4125 x 2 = 8250 ft³

Percentage of silo filled in 10 hours = (amount after 10 hrs / total amount) x 100

Substitute the values, we get

=(8250 /9068.32 ) x 100 %

=90.98 %

Thus, the percent of the silo filled with corn at 10 hours is 90.98%.

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Pure substances can be made of atoms that are attracted to each other or atoms that are not attracted to each other. Which type of pure substance can create elaborate structures? (1 point)

Atoms that are attracted to each other because the bonds that form between them can support the creation of the structure.

Atoms that are attracted to each other because they will mix together to form a mixture with a different structure.

Atoms that are not attracted to each other because they will form bonds with each other and create a larger structure.

Atoms that are not attracted to each other because they will stay still and end up laying on top of each other. ​​​​

Answers

The type of pure substances that can create elaborate structures is :

( D ) Atoms that are not attracted to each other because they will stay still and end up laying on top of each other.

What is an Elaborate structure ?

An elaborate structure is a complex structure formed by the combination of different unrelated parts. Atoms that are un attracted to each other are made of different parts therefore when they come together they will lay on each other, forming an elaborate structure which is complex in nature.

Hence we can conclude that the type of pure substance that can create elaborate structures is Atoms that are not attracted to each other because they will stay still and end up laying on top of each other.

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Light travels at 3.0 × 108 m/s in a vacuum. use the index of refraction for water to determine the speed of light in water. round your answer to the nearest tenth. × 108 m/s

Answers

Answer:

the answer is 2.3. I just answered this question and got it right.

Explanation:

The phenomenon bending of a wave as it crosses from one medium to another is said to be refraction. The speeds of light in the water will be 2.25×10⁸ m/sec.

What is the definition of refraction?

The phenomenon bending of a wave as it crosses from one medium to another is said to be refraction. The difference in density is the cause of the bending.

Refraction is a term that is used to describe the phenomenon of refraction."The change in direction of a wave traveling through one medium to another is known as refraction."

The following data are given in the problem;

C is the Speed of light in a vacuum =3×10⁸ m/sec.

n is an index of refraction for water = 1.333

v is the speed of light in the water=?

The index of refraction is the ratio of the speed of light in a vacuum to the speed of light in water. By the formula of the index of refraction.

[tex]n=\dfrac{c}{v}[/tex]

[tex]V=\dfrac{c}{n}[/tex]

[tex]V=\dfrac{3\times10^8}{1.333}[/tex]

[tex]V=2.25\times 10^8 m/s[/tex]

Hence the speed of light in the water will be 2.25×10⁸ m/sec.

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Activity 1. Circuit Designer

DIRECTIONS: Draw the corresponding circuit diagram and symbols using the given
number of components. If the diagram is given identify its components.
Please answer this correctly thank you.

Answers

The circuit diagram is a representation of an electric system. It represents the components of the system with symbols. Drawings in the attached file.

What is a circuit diagram?

The circuit diagram is an electrical circuit representation, including the sequence of electrical components or devices.

These diagrams make use of different symbols to represent the elements in the electrical circuit and make clear the connections to one another.

Some of the components composing the electrical circuits are

Single electric cell ⇒  It is represented with two perpendicular lines. The larger line indicates the positive terminal, and a shorter line represents the negative terminal.

The battery ⇒ combination of cells. Two or more cells together

NOTE: Some authors represent the battery as a single cell. You should draw your diagrams considering this. In my representations, I will consider a battery as two cells.      

Switch ⇒ plug key that allows or stops the current flow. It is represented as two circles and a line between them. If it is open, it is a perpendicular line. If it is closed, it is a horizontal line.

Wireconnection between devices. It is represented as a continuous line.

Bulb ⇒ devise that glows when connected to electricity. It might be represented as a cross in a circle.

The resistor regulates the amount of energy provided by the source. It is represented as a zig-zag line or a rectangle.

The ammeter ⇒ measures the current. Represented with an A.

Voltmeter ⇒ It measures the voltage. Represented with a V.

In the attached files, you will find the representations and the components. Please remember that a single battery is represented as two single cells. Make changes in your drawings if necessary.

 

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You’ll start by investigating how earth’s surface temperature varies. open my nasa data, and click on data set in the top left corner of the page. within the atmosphere category, select all data, then select temperature. now, select monthly air surface temperatures. after the new map appears on your screen, select the animate option near the top of the page, and then select ok to see the animation. set the time range on the animation for the most recent five years, and then click submit. you can control the speed of the animation with the controls beneath the map.

question 1
describe patterns you observe in earth’s surface temperature. how do these patterns change during the course of a year and from year to year? use lines of latitude and degrees celsius in your description.

Answers

Different patterns we observe in earth’s surface temperature due to angle, distance from the sun, latitude of the place and ocean currents.

Describe patterns you observe in earth’s surface temperature?

The Earth's surface experiences a range of temperature due to different conditions such as angle of the sun, distance from the sun, the latitude of the place, distance from the sea, altitude of the place and ocean currents.

So we can conclude that different patterns we observe in earth’s surface temperature due to angle, distance from the sun, latitude of the place and ocean currents.

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Good evening! Can someone please answer this, ill give you brainliest and your earning 50 points. Would be very appreciated.

Answers

Answer:

Gases that are very good at absorbing long wave photons of infrared light

Explanation:

Green house gases examples are Carbon monoxide, nitric oxide etc.These gases absorb long wave photons of infrared light of sun's rays They melts the glaciers and increase the sea level .

What type of electromagnetic waves cause sunburns?.

Answers

Answer:

ultraviolet waves

Explanation:

Our Sun emits light at all the different wavelengths in electromagnetic spectrum, but it is ultraviolet waves that are responsible for causing our sunburns.

Ultraviolet rays
Human skin is very sensitive to it

A 2.0-kilogram ball rolls down a ramp. if the ball accelerates at a rate of 12 m/s2, the net force causing the acceleration is:
a:6 newtons
b:10 newtons
c:12 newtons
d:24 newtons

Answers

Answer:

D

Explanation:

f = ma

2 x 12 = 24

answer could differ since it's rolling down a ramp. if an angle is given our approach differs.

An object rotates with an angular speed that varies with time, as shown in the graph. How can the graph be used to determine the magnitude of the angular acceleration α of the object? Justify your selection.


Subtract the greatest value of the angular speed from the smallest value of the angular speed, because α=Δω.

Subtract the greatest value of the angular speed from the smallest value of the angular speed, because a equals delta omega .

Determine the slope of the line from 0s to 2s, because the slope represents ΔωΔt.

Determine the slope of the line from 0 second to 2 seconds , because the slope represents the fraction delta omega over delta t .

Determine the area bounded by the line and the horizontal axis from 0s to 2s, because α=12ωΔt.

Determine the area bounded by the line and the horizontal axis from 0 second to 2 seconds , because alpha equals one half omega delta t .

The angular acceleration cannot be determined without knowing the rotational inertia of the object.

Answers

We can find it up angular velocity with respect to time graph .

As

[tex]\\ \rm\Rrightarrow m=\dfrac{\Delta \omega}{\delta T}[/tex]

[tex]\\ \rm\Rrightarrow \alpha=\dfrac{\Delta \omega}{\delta T}[/tex]

So we get

[tex]\\ \rm\Rrightarrow m=\alpha[/tex]

We need the slope in order to find angular acceleration

We can determine the angular acceleration of the object by taking the slope of the line in the plot of angular speed versus time because the change in linear here.

What is angular acceleration ?

The angular acceleration of an object is the measure of its rate of change in angular speed. Like the velocity, it a vector quantity and is characterized by a magnitude and direction.

The acceleration is the ratio of change in velocity to the time interval. From the graph of speed of an object versus the time taken, we can obtain the acceleration.

For a linear relation between the two quantities, the slope gives their ratio. Therefore, here, the slop of the line from 0 to 2 seconds represents the fraction delta omega over delta t. Hence, option D is correct.

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28. (a) A pendulum that has a period of 3.00000 s and that is located where the acceleration due to gravity is 9.79m/s2 is moved to a location where it the acceleration due to gravity is 9.82m/s2. What is its new period? (b) Explain why so many digits are needed in the value for the period, based on the relation between the period and the acceleration due to gravity.

The answer is "(a) 2.99541 s(b) Since the period is related to the square root of the acceleration of gravity, when the acceleration changes by 1% the period changes by (0.01)2=0.01% so it is necessary to have at least 4 digits after the decimal to see the changes." But please include the steps to each solution.

Answers

Answer:

See below ↓

Explanation:

Assuming the motion of a simple pendulum, the time period is given by

⇒ T = 2π√(L/g)⇒ T₁/T₂ = √(g₂/g₁)

The values we have

T₁ = 3 sg₁ = 9.79 m/s²g₂ = 9.82 m/s²

Solving

T₂ = T₁/√(g₂/g₁)T₂ = 3/√(9.82/9.79)T₂ = 3.004593 seconds

This many digits are needed because the acceleration is changed by a very small percentage (roughly 2 decimal places)So on taking the square root of the ratio of the gravity due to acceleration (2 values), 4 decimal places will be present at the very least

if predators and habitat do not change, which shade of frogs will have the greatest fitness

Answers

Answer:

The dark green frogs will

Explanation:

because they blend more within the night than any other frog or animal out there

I hope this helps

If predators and habitat do not change, the dark green frogs will have the greatest fitness.

What is predators?

Predators are organisms that hunt and kill other organisms for food. The organisms that are consumed by the predators are known as the prey.

The dark green frogs will have greatest fitness because they blend more within the night than any other frog or animal out there.

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You just explored speed. Now test your understanding. A car travels 85 km from Town A to Town B, then 45 km from Town B to Town C. The total trip took 1.5 hours. What was the car’s average speed? A. 65 km/h B. 87 km/h C. 131.5 km/h D. 2 km/h

Answers

Answer:

B. 87 km/h

Explanation:

We can find the average speed by using the relationship between speed, distance, and time.

Distance = Speed * Time

Reaarange this to obtain:

Speed = Distance/Time

Speed = (85+45)/1.5

Speed = 87 km/h


When a skydiver falls towards the Earth, the force of gravity from Earth pulls her towards the
Earth and she is obviously accelerating towards the Earth.
Can the reverse (the force of gravity pulls the Earth towards her and the Earth is accelerating
towards her) be true? Explain.

Answers

Answer:

yes

true

Explanation:

because earth is rotation

At a later time interval, the thrust force is 50N, the drag force is 20N, the lift force is 40N, and the weight (gravity) force is 40N.
25N
Drag
40N
Lift
50N
Thrust
40N
Weight
During this time interval, which forces are unbalanced?

Answers

During this time interval, the unbalanced forces are the downward forces which include drag force and weight of the object.

Net force on the object

The net force on the object is obtained by summing all the forces acting on the object.

Let the upward force = positive

Let the downward force = negative

Thrust force (upward) = 50 NDrag force (downward) = 20 NLift force (upward)  = 40 NWeight (downward) = 40 N

Net force = (50 N + 40 N) - (20 N + 40 N)

Net force = 90 N - 60 N = 30 N

Thus, during this time interval, the unbalanced forces are the downward forces which include drag force and weight of the object.

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I won the science fair; it was my first time entering.FragmentComplete Sentence Which nation was the first and only nation to land a spaceship on the moon?. Direcciones: Tienes que poner los verbos en el pretrito o imperfecto. En un bosque _______ (llenar) de flores y rboles haba un pueblo. Haba una princesa hermosa y fuerte. Ella _____ (ser) la princesa del rey azteca. Este pueblo _______ (creer) que los dioses _______ (controlar) la naturaleza, el universo, las guerras y la fertilidad. Una vez, el volcn grande _____(tener) humo saliendo de la cima. Todo el pueblo ______ (estar) nervioso. Ellos no ______ (saber) qu hacer. La princesa les ______ (decir) que Voy a sacrificarme a los dioses para salvar nuestra comunidad. El rey ______ (estar) orgulloso de ella porque _____ (ser) un honor de ser sacrificado a los dioses. El pueblo _______ (empezar) a prepararse para el sacrificio. Cuando el da ________ (llegar), la princesa _______ (estar) lista para hacer cualquier cosa para salvar la comunidad. El sacerdote ______ (hacer) el ritual. EL corazn de la princesa ____ (ser) una oferta a los dioses para cuidar al pueblo y parar el volcn. Todo el pueblo _______ (estar) relajado y triste con la muerte de la princesa. El corazn de la princesa ______ (parar) el humo del volcn y todo el pueblo _________ (empezar) a celebrar. Which abiotic component of its ecosystem did the owl in the picture above use to build a safe nest?OA. airOB. rocksOC. trees Systems of equations by graphing What would y = for this system? Where is the noun in this sentence: the patient harassed Dr Carter? HELP ME OUT PLS!!!!!!!!3) The motion of the Earth is modeled here as it moves on its axis and around the Sun. Which of these statements correctly identifies how the illustration supports the concepts of seasons on Earth? Select ALL that apply A) The tilt of the Earth is responsible for the seasons. B) The rotation of the Earth is responsible for the seasons. C) The proximity of the Earth to the Sun is responsible for the seasons. D) The revolution of the Earth around the sun is responsible for the seasons. E) The intensity of the sunlight on Earth is different as the Earth revolves around the sun Using digits, what time is represented by quarter to eleven? *Pls help me*Yasmine is trying to find an outfit for the first day of school. She has to choose from 3 pairs of skirts: one black, one pink and one orange. She also has five blouses: one with flowers, one with polka-dots, one gray, one white and one with words saying I love New York! How many possible outfits can she choose from? *Hint-create a probability table. please help tysm and no links How has discovering the properties of the protein miraculin affected people?A. It led people to try growing the plant that produces the protein in colder climates.B. It helped people explain how the sense of taste developed over time.C. It led people to find ways of using the protein to make sour foods taste sweet..D. It helped people understand how taste buds work find the missing side length please! Help! How do I fill out the box at the top of the page? This isn't making sense (I'm in 7th) When was jada pinkett smith diagnosed with alopecia?. Ana y su esposo hicieron una excursin de ecoturismo en la selva y visitaron las islas de san blas. I need help, please? I am just really confused about this. PLEASE HELP! CALCULUS Jake owns a garden supply store. his revenue at the end of last month was $12,200. what is Jake's run rate? At room temperature, dry ice (carbon dioxide, CO2) changes directly from solid to gas. What happens as the solid dry ice turns into carbon dioxide gas?A.CO2 molecules lose mass to become gas.B.CO2 molecules release heat energy to the air.C.CO2 molecules absorb heat energy from the air.D.CO2 molecules react with oxygen and become gas. The two different X in Y individuals plays a role in increasing genetic biodiversity