A man is sitting on a chair with wheels. He grabs a 2.1 kg book from the desk and throws
the book at a speed of 7.2 m/s. His chair moves backward. The man has a mass of 70 kg and
the chair has a mass of 9.2 kg. What is the speed of the man and the chair after the book is
thrown?

Answers

Answer 1

The speed of the man and the chair after the book is thrown is 0.2 m/s.

The given parameters:

mass of the book, m₁ = 2.1 kgspeed of the book, u₁ = 7.2 m/smass of the man, M = 70 kgmass of the book, m = 9.2 kg

The total mass of the man and the book is calculated as follows;

m₂ = 70 kg + 9.2 kg

m₂ = 79.2 kg

The speed of the man and the chair after the book is thrown is determined by applying the principle of conservation of linear momentum;

[tex]m_1 u_1 = m_2u_2\\\\u_2 = \frac{m_1u_1}{m_2} \\\\u_2 = \frac{2.1 \times 7.2}{79.2} \\\\u_2 = 0.2 \ m/s[/tex]

Thus, the speed of the man and the chair after the book is thrown is 0.2 m/s.

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Related Questions

Two electrons are separated by one cm. What is the ratio of the electric force to the gravitational force between them? (me = 9. 11 ´ 10-31 kg, ke = 8. 99 ´ 109 N×m2 /C2 , G = 6. 67 ´ 10-11 N×m2 /kg2 , and e = 1. 6 ´ 10-19 C) a. 2. 3 ´ 102 b. 1. 3 ´ 1020 c. 3. 1 ´ 1022 d. 4. 2 ´ 1042.

Answers

The ratio of the electric force to the gravitational force between the two electrons is [tex]4.2 \times 10^{42}[/tex].

The given parameters;

Mass of the electron, [tex]m_e[/tex]= 9.11 x 10⁻¹¹ kgCoulomb's constant, k = 8.99 x 10⁹ Nm²/C²Gravitational constant, G = 6.67 x 10⁻¹¹ Nm²/kg²Charge of electron, q = 1.6 x 10⁻¹⁹ CDistance between the two electrons, r = 1 cm

The electrostatic force between the two electrons is calculated as follows;

[tex]F_c = \frac{kq^2}{r^2} \\\\[/tex]

The gravitational force between the two electrons is calculated as follows;

[tex]F_g = \frac{Gm_e^2}{r^2}[/tex]

The ratio of the electric force to the gravitational force between the two electrons is calculated as follows;

[tex]\frac{F_c}{F_g} = \frac{kq^2}{r^2} \times \frac{1}{\frac{Gm^2}{r^2} } \\\\\frac{F_c}{F_g} = \frac{kq^2}{r^2} \times \frac{r^2}{Gm^2} \\\\\frac{F_c}{F_g} = \frac{kq^2}{Gm^2}\\\\[/tex]

[tex]\frac{F_c}{F_g} = \frac{(8.99 \times 10^9) \times (1.6 \times 10^{-19}))^2}{(6.67 \times 10^{-11} ) \times (9.11 \times 10^{-31})^2} \\\\\frac{F_c}{F_g} = 4.2 \times 10^{42}[/tex]

Thus, the ratio of the electric force to the gravitational force between the two electrons is [tex]4.2 \times 10^{42}[/tex].

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which term is most applicable to a discussion of angular momentum in the context of black holes?


A: Photon

B: Curvature

C: Spin

D: Time

Answers

Answer:

c:   spin

Explanation:

it's not curvature

The most applicable term to a discussion of angular momentum in the context of black holes is Spin. Thus, the correct option is C.

What is angular momentum of black holes?

Angular Momentum is defined as the property of any rotating object which is given by the product of the moment of inertia of an object and the angular velocity of the rotating object. Angular momentum is a vector quantity and it has both the magnitude and direction. The examples of angular momentum are the rotation and revolution of the Earth.

When the astronomers claim that they have estimated the spin of a black hole, this means they have measured its angular momentum. This is the total angular momentum of all the materials on the Universe that ever crossed the event horizon and got trapped inside it.

Therefore, the correct option is C.

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Help me quick!!! please!!

Calculate the power of an engine which raises a mass of 1000 kg to a height of 40 m in 10 s.

Answers

Answer:

39.240 W

Explanation:

Let's start by calculating the work done by the engine. We can assume that it is the same work done by the weight of the object to bring it from 40m to the surface: as much energy it takes to bring it up, the same ammount it takes to bring it down. Said work is [tex]w= \vec F\cdot \vec{h} = mg h = 1000 \times 9.81\times 40 = 392.400 J[/tex]

At this point we can simply apply the definition of power, that is [tex]P = \frac wt[/tex], to get the power of the engine is [tex]39.240 W[/tex]

Answer:

P=39200W

Explanation:

P=(mgh)/t

P=(40×9.8×1000)/10

P=39200W

A block with a mass of 6.0 kg is
held in equilibrium on an incline
of angle θ = 30.0° by a horizontal
force, F, as shown in the figure.
Find the magnitudes of the
normal force on the block and of F. (Ignore friction.)

Answers

(a) The normal force on the block is 50.92 N.

(b) The horizontal force on block keeping it in equilibrium is 29.4 N.

The given parameters;

mass of the block, m = 6 kgangle of inclination, θ = 30.0°

The normal force on the block is calculated as follows;

[tex]F_n = W \times cos(\theta)[/tex]

where;

W is the weight of the block

[tex]F_n = mg \times cos(\theta)\\\\F_n = 6 \times 9.8 \times cos(30)\\\\F_n = 50 .92 \ N[/tex]

The horizontal force on block keeping it in equilibrium is calculated as follows;

[tex]F- F_x = 0\\\\F-mgsin\theta= 0\\\\F = mgsin\theta\\\\F = 6 \times 9.8 \times sin(30)\\\\F = 29.4 \ N[/tex]

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2. If Joe rides his bicycle in a straight line for 15 min with an average velocity of 12.5 km/h south, how far has he ridden?

Answers

Answer:

3.125 Kilometers

Explanation:

To answer this you just multiply 12.5 by .25 (since 15 minutes is a quarter of an hour) to get 3.125 kilometers ridden.

Study the three pieces of evidence for the Big Bang in this activity carefully. What is common to all these pieces of observable evidence and why does this make them much more powerful than if they did not have this common feature?

Answers

Answer:

Explanation:

the measured abundances of elementsthe observed expansion of spacethe discovery of cosmic wave background

The common observable evidence are:

the measured abundances of elementsthe expansion of spacethe cosmic wave background

What is big bang?

The big bang is the theory which explains that how the universe began. It says that the universe began with just a single point. It went on expanding and stretched to grow as large as possible. It is still now expanding.

The big bang consist of fully dark matter, interstellar gases or dust. The big bang is increasing just because in universe there is abundant of hydrogen and helium.

The radiations come from the big bang. These rays are also called as cosmic wave. This big bang is still on it way of expanding more.

Thus, the observational evidence are the measured abundances of element, the expansion of space and the cosmic wave background.

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given. force of 88N and an acceleration of 4 m/s 2 what is the mass?

Answers

Mass, m=22 kg
It is given that Force, F = 88N
Acceleration, a=4 m/s 2

Describe the changes that occur inside a helium balloon as it rises from sea level

Answers

Answer:

The balloon expands in the number of particles per cubic centimeter decreases. This happens because as it expands there is a decrease in the density of area. The Dead Sea is a solution that is so dense that you easily float on it.

the primary factor in decreasing the kinetic energy of an object is to

Answers

Answer:

Decreasing the velocity

Explanation:

The primary factor in decreasing the kinetic energy of an object is to decrease the velocity of the object.

What is Kinetic energy?

The kinetic energy of an object is the energy which it possesses due to the motion of the object. Kinetic energy is defined as the work which is needed to accelerate an object of a given mass from the state of rest to its stated velocity and direction. Gain of the energy during the acceleration of an object, the body maintains this kinetic energy unless its speed changes and the object accelerates.

The kinetic energy is directly proportional to the mass and the velocity of the object. The primary factor which is responsible for the decrease in the kinetic energy of an object is to decrease the velocity of the object.

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You throw a can of cranberry sauce straight up in the air with an initial velocity of 12 m/s. What is the maximum height the baseball reaches above your head.

Answers

Answer:

Δx=7.35m

Explanation:

This is a free fall problem (g= -9.8 m/s²).

Displacement: ? <--- what you're trying to find (max height)

Initial Velocity: 12 m/s

Final Velocity: 0 m/s <-- since the can will land back in your hands

Time: Missing <-- not needed to solve

Acceleration: -9.8 m/s²

The equation that you will use is vf²=vi²+2aΔx

Now plug the information into the equation!

(0m/s)²=(12m/s)²+2(-9.8m/s²)Δx

Multiply the 2 with the acceleration (-9.8m/s²)

(0m/s)²=(12m/s)²-19.6m/s²Δx

Now you need to square the final and initial velocity

0m/s=144m/s-19.6m/s²Δx

Move 144 to the other side of the equal sign

-144m/s=-19.6m/s²Δx

Divide both sides by -19.6m/s²

7.346m=Δx

You can round it to the tenth or hundreth place, up to you!

For this example, I'll round to the hundredth...

Δx=7.35m

I would double check this answer or review it yourself to see if it's correct.

Good luck with your studies!

A 75.0 kg man pushes on a 500,000 kg wall for 250 s but it does not move.

Answers

[tex]▪▪▪▪▪▪▪▪▪▪▪▪▪  {\huge\mathfrak{Answer}}▪▪▪▪▪▪▪▪▪▪▪▪▪▪[/tex]

The work done in the given case is 0

[tex] \large \boxed{ \mathfrak{Step\:\: By\:\:Step\:\:Explanation}}[/tex]

For calculating the work done by an object we apply the formula, that is ~

[tex]f \times s \times \cos( \theta) [/tex]

where f represents force applied, and s represents displacement.

but here, the displacement is zero since the wall didn't move at all, Therefore If we plug it's value as 0, we get

[tex]f = 0 \times s \times \cos( \theta) [/tex]

hence,

[tex]work \: done = 0[/tex]

Solution:Here, though the man is applying force on the wall, the work done is zero. This is because work is said to be done only when a force acting on a body produces motion in it in the direction of the force applied. Here, the man is trying to push the wall with a great force. He might fell exhausted after some time and say that he has done a lot of work. But in terms of physics, he has done no work because the force applied by the person has not produced any displacement. We know, work done = force × displacement. If displacement is zero, then work done is zero.

So therefore, we can conclude that the man hasn't done any work.

Hope it helps.

Do comment if you have any query.

Rubies are used in electronics.
Please select the best answer from the choices provided
) Т
) F

Answers

False, rubies are not used in electronics because they are bad conductors.

help -----------------------------------------

Answers

Answer:

H,G,E,D,C,B,A,I,F

Explanation:

F is an ignious intrusion and I cross cuts H to A so it must be newer.

3. Would prudent to do an observatory M 82 for this class?​

Answers

Answer: Yes,

If you need any other thing let me know, I'll still be on

Explanation:

State a hypothesis about your estimated daily water use.

Answers

Answer

Estimates vary, but, on average, each person uses about 80-100 gallons of water per day, for indoor home uses.

Explanation:

If the submarine intends to submerge to a depth of 150 m, what pressure must it be designed to withstand

Answers

Explanation:

Hydrostatic pressure, P = hdg where d is density if the liquid ( water)

P= 150m × 1000kgm-3 × 10ms-2

P= 1.5 ×10^6 Pa

Prove that the two equations shown below are equivalent.​

F = ma and F = p/t​

Answers

Newton’s Second Law of Motion is defined as Force is equal to the rate of change of momentum. For a constant mass, force equals mass times acceleration.

[tex]\Delta p = mv - mu \\\\\implies \Delta p = m(v-u) \\\\F = \dfrac{\Delta p}{\Delta t} = \dfrac{m(v-u)}{\Delta t} = ma[/tex]

F = ma is the formula of Newton’s Second Law of Motion.

To prove Newton's second law of motion,

Given Force F = Δp/Δt

What is relation between F = ma and F = Δp/Δt?Newton’s Second Law of Motion is defined as Force is equal to the rate of change of momentum. The second law of Newton can be described as the acceleration of an object which produces a net force is directly proportional to the magnitude of the net force, in the same path i.e., direction as the net force, and inversely proportional to the mass of the object.As the acceleration has its magnitude and direction it is a vector quantity.

Proof for F=ma

     Let us consider an object of mass m, moving along a straight line with an initial velocity u, final velocity v and it has some particular time t and thus Momentum can be related as,

For initial velocity u, p1 = m × u

The final velocity v, p2 = m × v

The change in momentum can be expressed as

p2 – p1 = (m × v) – (m × u)

p2 – p1 = m (v – u)

Here, we know that the rate of change of momentum with respect to time is proportional to the applied force.

The applied force F,

F ∝ [m (v – u)]/t

F ∝ m × a

As acceleration (a) is the rate of change of velocity with respect to time.

F = k × m × a

F = ma

where k can be the constant.

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Why is wrestling ring floor always softThis is physics

Answers

Answer:

So the people in the ring don't get hurt or break anything on impact once they hit the floor

PLEASE ANSWER NEED HELP!!!!!!!! PLEASE THE CORRECT ANSWER!!!!!!


Zhiyu wants to start an exercise program. He knows that he should talk to his doctor, but he cannot get an appointment for several weeks. He does not have any health conditions. What is the BEST advice for Zhiyu?
A.
All exercise needs to be medically supervised, so he must wait.
B.
There is always a risk of injury, so he needs professional advice before he starts.
C.
He can start slowly with low impact activity like walking or light weightlifting.
D.
He should do whatever he feels like; his body will let him know if he overdoes it.


PLEASE NO LINKS OR I WILL REPORT YOU

Answers

Answer:

c

Explanation:

What quantity is represented by the mass number minus the atomic number?.

Answers

Answer:

Mass = mass of nucleus

Atomic Number = number of protons (charge) of nucleus

Mass - Atomic Number = number of neutrons

Suppose you were able to take measurements of current through the
resistor and voltage across the resistor. Your record of numerical values is written in a

tabular data below​

Answers

Answer:

  see attached

Explanation:

It will be easier to plot the data if you have grid lines to work with.

In the attached, we had to reverse the order of entries in the table, because the graphing program likes the independent variable listed first.

A fairly efficient steam turbine engine fired by coal is used to drive an electric generator. The generator operates between 2100°C and 385°C.

(a) Determine the maximum possible efficiency of the engine.


Answer: 72.3 %


Formula:

e = 1 - (Tc / Th) = 1 - (Qc / Qh) = ( W / Qh)


Explanation: Unsure??


(b) The engine absorbs 1.15 105 J from the hot reservoir every second. If the actual efficiency of the engine is 40.3%, determine the mechanical power the engine delivers.


Answer: 46 kW


Explanation:

Energy absorbed by the engine (J) * actual efficiency of the engine (%) = mechanical power the engine delivers (kW)


How does 1 - (385/2100) = 72.3 % ?
What do I Plug in to make e = 72.3 %

Answers

Use kelvin not celsius

C + 273 = K

This will fix my problem of the equation not making sense.

I'll give brainliest​

Answers

Good luck dude hahaha

Answer: figuratively speaking both the lines for the force Q and force P is equal.

lonic Naming Practice
Write the name of the following chemical compound:
Na3Cl1

Answers

Answer:

sodium chloride. .....

Ionic naming practice: Na3Cl1= Sodium Chloride

Da 6.0 kg wooden crate slides across a wooden floor
at a speed of 2.4 m/s, it it takes an applica force
of 25 N to keep it going at a steady speed. What is the
coe of kinetic friction between the floor and crate?

Answers

Answer:coe?

Explanation:

The product of pressure and volume of any gas equals a constant, k. What variable(s) must not change in order for the value of k to remain constant

Answers

The variable is temperature

please answer right please

Answers

Answer:

i think its A

Explanation:

I hope this helps :)

An "energy bar" contains 26 ggof carbohydrates.How much energy is this in joules?

Answers

I’m it’s about 3.4878 energy in joules

This should be pretty easy i think.

Describe the components within the system involved in the collision between pilot and landing zone.

Answers

Answer:

its a sure for not but i think its a 192583

A transformer is being built to triple the voltage produced. Which data are collected to investigate whether the transformer can achieve the goal? (1 point)

A) the ratio of the number of turns in the primary and secondary coils

B) only the number of turns in the secondary coil and the magnetic field of the core

C) only the number of turns in the primary coil and the magnetic field of the core

D) the ratio of the number of turns in the primary and secondary coils and the magnetic field of the core

Answers

Answer:

the ratio of the number of turns in the primary and secondary coils.

Explanation:

hope i'm not too late!!

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HELPPPPPPP plssssssss In the diagram, HELP ME OUT PLEASE!! Hormones help control mood, growth and development, the way our organs work, metabolism, and reproduction a) True b) False NFPA 780, Standard for the Installation of Lightning Protection Systems provides information on the installation of _____ for lightning protec-tion systems [250.4(A)(1)]. {6x+5y=4{6x-7y=-20solve by elimination Dana ate her trail mix. she found that 28% of the trail mix is raisins. What is 28% of 7 ounces What is the Bill of Rights?The first amendment to the Constitution, which is actually a group of ten amendmentsThe list of laws that people of the United Stated needed to followThe document that replaced the ConstitutionThe document that replaced the Articles of Confederation Which equation represent this statement? 5 less than twice a number is 3 2n - 5 = 32n - 3 = 5 5 - 2n = 33 - 2n = 5 13- pls help with this pre-algebra problem is urgent scients is a combination of three things what are they? Mr. Green is still repairing that old, rundown house he recently purchased. He finally fixed that leaky faucet in the kitchen, but now the bathroom faucet is leaking. Hes wondering if the dripping rate is the same as the kitchen, so again he starts his observations. However, this time he notes that for the bathroom faucet, 8 ounces of water dripped in 12 minutes.A) At this rate, how many ounces of water will drip in a day? What impact did President George Washington have on setting precedents for the office of the President? HALPPPPP At the first step upon the cold surface, Buck's feet sank into a white mushy something very like mud. He sprang back with a snort. More of this white stuff was falling through the air. He shook himself, but more of it fell upon him. He sniffed it curiously, then licked some up on his tongue. It bit like fire, and the next instant was gone. This puzzled him. He tried it again, with the same result. The onlookers laughed uproariously.What does this excerpt reveal about the setting of the story?1It is a work site with dangerous equipment.2It is a tourist destination with unfamiliar sights.3It is a more heavily populated town than Buck has ever seen.3It is a colder climate than Buck has ever experienced.NO LINKS PLZZZ The ratio of the number of girls to the number of boys is 3:5 . if the number of boys os 12 more than the number of girls ,calculate the total number of students in the class. Fred buys flags from a manufacturer for $12.50 dollars and then sellsthem in his store for a 26% markup.What price do his customers pay fora flag? which statement best describes the circadian rhythm? On the way to her babysitting job, Mary rode her bike for the first mile. She stopped at a traffic light and waited a few minutes for the traffic light to turn green. She then walked her bike across the street and up a short steep hill. Finally, she rode the bike at a constant speed for one more mile. If Mary created a graph of her time and distance, which statement describes the part of her graph that would show no change in distance?A.Mary used her bike to ride the first mile.B.Mary stopped and waited for the traffic light to turn green.C.ary walked her bike across the avenue and up a short hill.D.Mary rode her bike at a constant speed for one mile. Sara poured 3/4 of the juice from a 2 liter bottle while serving guest party.How much juice, in liters, is still left in the bottle Find the area of a circle with a radius of 6 feet. Use 3.14 for pi 1) The stomach is an organ of the digestive system. It is made up of several types of tissue that work together. What kinds of tissue make up the stomach? Choose ALL that apply.A) nervousB) smooth muscleC) dense connectiveD) simple columnar epithelialE) stratified squamous epithelial