a cave rescue team lifts an injured spelunker directly upward and out of a sinkhole by means of a motor-driven cable. the lift 1s performed in three stages, each requiring a vertical distance of 10.0 m: (a) the initially stationary spe- lunker is accelerated to a speed of 5.00 m/s; (b) he is then lifted at the constant speed of 5.00 m/s; (c) finally he is decel- erated to zero speed. how much work is done on the 80.0 kg rescuee by the force lifting him during each stage

Answers

Answer 1

Answer:

Below

Explanation:

Work = force x distance   ==>  the forces during the 3 stages are different

a)   I will assume accel is constant for the first 10 m

             Average velocity = 5/2 = 2.5 m/s

               10 m / 2.5 m/s = 4 seconds

                 then a = 5 m/s / 4 s = 1.25 m/s^2   <==this accel is added to 'g'

                          F = ma

                                = 80 * (9.81 + 1.25) = 884.8 N

                        W = 884.8 * 10 = 8848 J

b)   This one is easier    W = F * d =  (80)(9.81)(10) = 7848 J

c)    Now we decelerate  at 1.25 m/s^2 <==== this SUBTRACTS from g

           W = ( 80 )(9.81-1.25)*10 = 6848 J  

           

             

Answer 2

Answer:

C

Explanation:

Positive acceleration describes an increase in speed; negative acceleration describes a decrease in speed. C


Related Questions

Tyson has been assigned to the offensive line as a left guard on his football team which requires him to make explosive movements and push other players body weight in a specific direction. Which sport skill does he demonstrate as his dominant skill based on this position assignment?

Answers

Answer:

The answer is power.

Explanation:

because in the reading it says it's his dominant skill.

and beacuse i got it right on the test.

Answer:

The answer is power.

Explanation:

A baseball sits motionless near first base on a baseball diamond. What statement best explains why the baseball remains motionless?

Answers

Answer:

Explanation:

Newton's first law states that, if a body is at rest or moving at a constant speed in a straight line, it will remain at rest or keep moving in a straight line at constant speed unless it is acted upon by a force. This postulate is known as the law of inertia.

hope this helps :))

There is no force acting on the baseball the statement best explains why the baseball remains motionless.

What is inertia?

A body wants to remain in its original position until or unless the external force is not applied to it. Such a phenomenon is known as inertia.

Newton's first law asserts that if a body is at rest or traveling at a uniform speed in a straight direction,

It will remain at rest or continue to move in a straight path at a constant speed until acted on by a force. This is referred to as the law of inertia.

There is no force acting on the baseball the statement best explains why the baseball remains motionless.

Hence option B is correct.

To learn more about the inertia refer to the link;

https://brainly.com/question/3268780

1.Wave motion that is parallel to the wave direction is described 

as_____________ wave.

2. The time to make one complete cycle is _____________.

3. The distance between successive crests of a wave is __________.

4. Wave motion that is perpendicular to wave direction describes a

       _____________ wave.

5. The number of waves that passes a given point in time is__________.

6. ____________ is a kind of wave that does not need a medium.

7. The highest point of a wave is called ___________.

8. The unit for frequency is ____________.

9. The part of a longitudinal wave where there are fewer particles is     

    called______________.

10. A region in a medium of longitudinal wave where molecules are 

      packed is called _____________.​

Answers

Answer:

Explanation:

A wave is a phenomenon that travels through a material medium without any permanent effect on the medium. It can be classified as mechanical or electromagnetic waves. And the two major types are transverse and longitudinal.

From the given question;

1. Longitudinal waves e.g sound waves, waves in a spring'

2. Frequency (number of cycles per second).

3. Wavelength of the wave. Measured in meters.

4. Transverse waves e.g light waves, water waves.

5. Wave speed.

6. Electromagnetic waves e.g ultraviolet waves, X-rays etc.

7. Amplitude.

8. Hertz.

9. Rarefaction

10. Compression

A wave is a phenomena that flows across a material medium without leaving any lasting mark.

1.Wave motion that is parallel to the wave direction is described

as longitudinal wave.

What is wave?

A wave is a phenomena that flows across a material medium without leaving any lasting mark. Mechanical or electromagnetic waves can be used to classify it. Transverse and longitudinal are the two main forms.

1.Wave motion that is parallel to the wave direction is described

as longitudinal wave.

2.Frequency is defined as the number of cycles per second.. The time to make one complete cycle is frequency.

3.Wavelength of the wave is measured in meters.The distance between successive crests of a wave is wavelength.

4. Examples of Transverse waves are light waves, water waves.. Wave motion that is perpendicular to wave direction describes transverse wave.

5.The number of waves that passes a given point in time is Wave speed.

6.Examples of Electromagnetic waves are ultraviolet waves, X-rays etc.

Electroimegnetic wave is a kind of wave that does not need a medium.

7.The highest point of a wave is called amplitude.

8.The unit for frequency is Hertz.

9. A region in a medium of longitudinal wave where molecules are Rarefaction.

10.  A region in a medium of longitudinal wave where molecules are

packed is called compression.

To learn more about the wave refer to the link;

https://brainly.com/question/3004869

What is addictive about vaping?

Answers

Answer:
The last one, nicotine from tobacco

Answer:

nicotine obviously

Explanation:

!Necesito ayuda:Un movil parte del reposo y en 5seg adquiere una rapidez de 12m/seg.Calcular la distancia recorrida.

Answers

Answer:

Distancia = 60 metros

Explanation:

Dados los siguientes datos;

Velocidad inicial = 0 m/s (ya que comienza desde el reposo)

Velocidad final = 12 m/s

Por lo tanto, velocidad total = velocidad inicial + velocidad final

Velocidad total = 0 + 12 = 12 m/s

Tiempo = 5 segundos

Para encontrar la distancia recorrida;

Distancia = velocidad total * tiempo

Sustituyendo en la fórmula, tenemos;

Distancia = 12 * 5

Distancia = 60 metros

Select the correct answer. The Cretaceous-Paleogene was a mass extinction event in which nearly every single large, land-dwelling dinosaur went extinct. Which of the following did not result from this extinction event? A. Diverse species of animals began to evolve. B. Meteorites struck the region that Mexico now occupies. C. Clouds of dust and gas billowed into Earth’s atmosphere. D. Ecological niches were left empty but with the potential to be filled.

Answers

Answer:

d

Explanation:

because

Answer:

the answer is B. Meteorites struck the region that Mexico now occupies.

Explanation:

i got it right on plato

An object has an angular velocity of 1.0 rad and an angular acceleration of 0.5 rad/s. Is the speed of its rotation increasing or decreasing?

Answers

Answer:

increasing

Explanation:

Given that,

Initial angular speed =1 rad/s

Angular acceleration = 0.5 rad/s²

We know that the angular acceleration is given by :

[tex]\alpha =\dfrac{\omega_f-\omega_i}{t}[/tex]

Where

[tex]\omega_f[/tex]city and t is time is the final angualr velo

As the angular acceleration of the object is positive. It means that the final speed of the object is more than that initial. As a result, the speed of its rotation is increasing.

An RC circuit consists of a resistor with resistance 1.0 kΩ, a 120-V battery, and two capacitors, C1 and C2, with capacitances of 20.0 μF and 60.0 μF, respectively. Initially, the capacitors are uncharged; and the switch is closed at t = 0 s. How much charge will be stored in eah capacitor after a long time has elapsed (capacitor one 2.4 x 10^-3 C) (capacitor 2 7.2 x 10^-3 C) and what will the total charge on both capacitors two time constants after the switch is closed? (8.3 x 10^-3)

Answers

Answer:

[tex]Q_t= 8.3 * 10^3 C[/tex]

Explanation:

From the question we are told that:

Resistor [tex]R=1000ohms[/tex]

Voltage [tex]v=120_V[/tex]

Capacitance of c_1 [tex]c_1=20 \mu F[/tex]

Capacitance of c_2 [tex]c_2=60 \mu F[/tex]

Time [tex]t=0[/tex]

Generally the equation for charges is mathematically given by

[tex]For C_1\\Charge\ on\ C_1 = CV = 20*120 = 2400 μC = 2.4 x 10^-3 C\\Charge\ on\ C_1 = 2400 μC = 2.4 x 10^-3 C\\Charge\ on\ C_1 = 2.4 x 10^-3 C\\[/tex]

[tex]ForC_2\\Charge on C_2 = 60*120 =7200 μC = 7.2 x 10^-3\\Charge on C_2 = 7.2 x 10^-3[/tex]

Generally the equation for voltage across capacitors is mathematically given by

[tex]V_c(t)=V(1-e^{-t/RC})[/tex]

[tex]C=C_1+C_2=80 \mu f\\t=2RC=>160000s[/tex]

[tex]V_c(t)=120(1-e^{-(160000)/1000*(80)})[/tex]

[tex]V_c(t)=103.7598[/tex]

Generally the equation for charges is mathematically given by

[tex]Q1(t) = C1Vc(t)\\Q1(t) = 20*103.7598\\Q1(t) = 2075.196\\\\Q2(t) = 60*103.7598\\Q2(t) = 6225.6\\[/tex]

Generally the equation for total charges [tex]Q_t[/tex] is mathematically given by

[tex]Q_t=Q1(t)+Q2(t)[/tex]

[tex]Q_t= 8.3 * 10^3 C[/tex]

How do you rationalize the tension being used in Tennis Racket strings using the concept of impulse and momentum?

Answers

Answer:

The momentum, ΔP, and therefore, kinetic energy given to the ball in a serve is the result of the product of the tension force, 'F', in the string and the time of contact, Δt, between the ball and the string

ΔP = F × Δt

Explanation:

The impulse, ΔP, is the produce of the force, 'F', applied to a body for a given period of time, Δt', that gives motion to the body, and it is equal to the change of momentum of the body

ΔP = F × Δt

The momentum, 'P', of a body is the product of the mass, 'm', of the body and its velocity, 'v'

P = m × v

Tension is the axial pulling force of a string

T = Axial Force, F[tex]_{axial}[/tex]

The tension used in Tennis Racket strings is between 40 to 65 lbs.

When high tension is used in the string, the string is taut, and the contact duration between the Racket string and the ball is minimal, and the player needs to use more force to obtain a high momentum, and therefore, energy in the ball, which reduces control, and increase stress, as force is more emphasized

When low tension is used in the string, the Tennis Racket strings are more elastic. During a serve, the ball pushes the strings further back into the racket, such that the ball spends more time in contact with the string, (Δt is larger), and therefore, the impulse, F·Δt = ΔP, given to the ball is larger, therefore, the ball has a larger change in momentum, and therefore more energy in the intended direction.

However, a very slackened string will increase the increase area and time (large Δt) of contact of the ball and the racket such that the force given to the ball, F = ΔP/(large Δt) is reduced and therefore reduce the likelihood of gaining points from a serve against an opponent with a much forceful return of a serve.

clarify this statement acceleration due to gravity of the Earth is 9.8m/s square​

Answers

Answer:

it means that velocity of a body rises by 9.8m/s each second if the air resistance is nrelated

mark me

Minh spent the weekend on his Wii and now has carpal tunnel syndrome. His 120 V outlet has an electrical current of 8A. What is the resistance in the Wii?

Answers

The resistance is 15 ohms.

Also, it's dissipating 960 watts whenever it's turned on. So it's almost as hot as a toaster, and Minh no longer has hands.

do opposite poles repel
true or false?

Answers

Answer:

false

Explanation:

like poles repel and opposite poles attract. :)

It's False

Opposite poles attractc each other.

Same poles repels each other.

7. Thermal energy depends upon the______ and _____ of an object?

Answers

:

Please give me brainly,

The thermal energy of an object depends on three things: 4 the number of molecules in the object 4 the temperature of the object (average molecular motion) 4 the arrangement of the object's molecules (states of matter). The more molecules an object has at a given temperature, the more thermal energy it has.

Mass and Temperarture

I am pretty sure that is right if Not sorry

Have a great day.

A 30 gram ball rolls along a flat surface at a constant speed in the same direction over 4 meters in 20 seconds. Which is the speed of the
ball? (speed = distance = time)
A. 0.2 meters per second
OB. 0.5 meters per second
c. 20 meters per second
D. 80 meters per second


Please answer this FAST!

Answers

speed = distance/time = 4 meters / 20 seconds = 0.2 meters per second

If a girl carries groceries up a flight of stairs, is she doing work on the groceries? Explain.​

Answers

Answer:

Explanation:

Yes she is doing work. With or without the groceries, she is still doing work. She does more work with the groceries than without because Work is defined by F which is defined by mass. The mass increases with the groceries.

The work done is against the force of gravity.

How does the mass of a satellite, moon or asteroid affect its orbital speed?

Answers

It would be B, the greater the mass, the more fast the orbiting object will move

At am outdoor market, a bunch of bananas is set into oscillatory motion with an amplitude of 29.8981 cm on spring with a spring constant

Answers

Answer:

Hello your question lacks some very vital information hence I will give you a general equation where you can input the missing values and get your answer

answer :  mass of Bananas ( m ) = [tex]\frac{A^2}{V^2} * K[/tex]

To calculate for weight of Bananas  = m * g      where g = 9.8

Explanation:

Given an amplitude ( A )= 29.8981

Spring constant = x ( unknown )

maximum speed of Bananas( v ) = wA  ( unknown )

question : calculate the weight of the bananas

First  step : calculate the period of oscillation

T = [tex]\frac{2\pi }{vA}[/tex] --- ( 1 )

next step : express T in terms of mass ( m ) of the bananas

= [tex]2\pi \sqrt{\frac{m}{k} } = \frac{2\pi }{vA}[/tex]

∴ m/k = A^2 / v^2

hence  mass of Bananas ( m ) = [tex]\frac{A^2}{V^2} * K[/tex]

To calculate for weight = m * g

The _____________ variable is observed, measured, and affected by the independent variable.​

Answers

the dependent variable

Answer: It would be the dependent variable.

Explanation:

The dependent variable is limited and can be affected by the changes and manipulation of the independent variable.

why doesn't every planet have a moon?​

Answers

Answer:

Up first are Mercury and Venus. Neither of them has a moon. Because Mercury is so close to the Sun and its gravity, it wouldn't be able to hold on to its own moon. Any moon would most likely crash into Mercury or maybe go into orbit around the Sun and eventually get pulled into it.

What is the net force if you pull a cart to the right with 5N of
force and a friend pushes the left to the left with 5 N of force

Answers

Answer:

In this case the net force is zero.

According to Newton's third law of motion: For every action, there is an equal and opposite reaction. In this case the net force is zero.

Explanation:

Hope this helps!! :)

Dones
Which statement best explains the similarity in the arrangement of the bones in these two structures?
O The bones of all animals are similarly arranged
O The bones of animals that take in oxygen are similarly arranged.
O Humans and whales use these structures to perform the same functions.
Humans and whales inherited these structures from a common ancestor.

Answers

The correct answer is the last option- inherited from common ancestor

Iron ball sinks in water but not in mercury. Why?

Answers

Answer:

mercury is more dense

Explanation:

Explanation:

Iron ball sinks in water but not in mercury because of the difference in the density iron used in iron ball. The iron ball has more density than water and less than the mercury.

Hence, Iron ball sinks in water but not in mercury.

-TheUnknownScientist

A car travels for 10s at a steady speed of 20 m/s along a straight road. The traffic lights ahead change to red, and the car slows down with a constant deceleration, so that it halts after a further 8s.

Answers

Answer:

The right solution is "2.5 m/s²". A further explanation is given below.

Explanation:

The given values are:

Initial velocity,

= 20 m/s

Final velocity,

= 0 m/s

Time,

= 8 s

As we know,

⇒  [tex]Acceleration=\frac{Final \ velocity-Initial \ velocity}{2}[/tex]

On substituting the values, we get

⇒                       [tex]=\frac{0-20}{8}[/tex]

⇒                       [tex]=\frac{-20}{8}[/tex]

⇒                       [tex]=-2.5 \ m/s^2[/tex]

Two coins lie 1.5 meters apart on a table. They carry identical electric charges. Approximately how
large is the charge on each coin if each coin experiences a force of 2.0 N

Answers

I don’t have any of the problem I can get it to my computer for my work

The charge on each coin is equal to [tex]2.50 \times 10^{-10}\;Coulomb[/tex]

Given the following data:

Force = 2.0 NewtonRadius = 1.5 meters

To determine the charge on each coin, we would apply the law of electrostatic forces:

Mathematically, the law of electrostatic forces is given by the formula:

[tex]F = \frac{kq_1q_2}{r^2}[/tex]

Note: [tex]q_1 = q_2[/tex] (since the coin carry identical electric charges).

Therefore, the formula becomes:

[tex]F = \frac{k(2q)}{r^2}[/tex]

Making q the subject of formula, we have:

[tex]q=\frac{Fr^2}{2k}[/tex]

Substituting the given parameters into the formula, we have;

[tex]q=\frac{2 \times 1.5^2}{2 \times 8.99 \times 10^9}\\\\q=\frac{2 \times 2.25}{2 \times 8.99 \times 10^9}\\\\q=\frac{4.5}{17.98 \times 10^9}\\\\q=2.50 \times 10^{-10}\;Coulomb[/tex]

Read more on charge here: https://brainly.com/question/4313738

Which of the following best describes the term thermal energy? Choose one: A. The energy of an object in motion due to its mass B. The kinetic energy of atoms, ions, and molecules C. The energy stored in an object because of its position D. The energy a particle has because of its charge and its position relative to another particle Part 2 (0.5 point)See Hint Which of the following best describes the term electrostatic potential energy?

Answers

Answer:

The correct option is (d).

Explanation:

The energy a particle has because of its charge and its position relative to another particle is called thermal energy. It is the energy that comes from heat. This is generated by the movement of the particles in an object.Thermal energy is the energy an object or system has due to the movement of particles within.

Hence, the correct option is (d).

The thermal energy is related to the kinetic energy of atoms, ions, and molecules.

What is thermal energy?

The thermal energy of any material is defines as the increase in the internal energy of the material.

When ever heat is given to the material, the atoms and the molecules in the material gains energy and moves with a kinetic energy.

The increase in kinetic energy allows the atoms and the molecules to move with higher velocities in the material, and they collide with each other, thus the temperature of the material increases.

Thus the thermal energy is related to the kinetic energy of atoms, ions, and molecules.

To know more about Thermal energy follow

https://brainly.com/question/19666326

If a car moves 12 km north, 19 km east, and 12 km south, what is its displacement?

Answers

Answer:

19 km.

..............

Explanation:

.....

Answer:The Distance is 43 and displacement is 5km south

Explanation: To find the distance you add up all the numbers which was 43 and to fine the displacement subtract all the numbers and since all the other numbers were out expect for -5 which was south you would put 5 km south , if the number has a negative on it , it doesnt matter.

A 20 g block of ice is cooled to −65 ◦C. It

is added to 570 g of water in an 76 g copper

calorimeter at a temperature of 26◦C.

Find the final temperature. The specific

heat of copper is 387 J/kg ·

◦C and of ice is

2090 J/kg ·

◦C . The latent heat of fusion of

water is 3.33 × 10^5

J/kg and its specific heat

is 4186 J/kg ·

◦C .

Answer in units of ◦C.

Answers

Answer:

The final temperature is approximately 23.55°C

Explanation:

The given parameters are;

The mass of the ice block, m₁ = 20 g

The initial temperature of the block, T₁ = -65°C

The mass of the water to which the block is added, m₂ = 570 g

The mass of the copper container containing the water, m₃ = 76 g

The initial temperature of the water and the copper, T₂ = 26°C

The specific heat capacity of copper, c₃ = 387 J/(kg·°C)

The specific heat capacity of ice, c₄ = 2,090 J/(kg·°C)

The latent heat of fusion of ice, l = 3.33 × 10⁵ J/kg

The specific heat capacity of water, c₁ = 4,186 J/(kg·°C)

We have;

ΔQ = m₁·c₁·ΔT + m₁·l = m₂·c₂·ΔT + m₃·c₃·ΔT

Therefore, we get;

20 × 2,090 × -65 +  20 × 3.33 × 10⁵ + 20 × T × 4,186  = 570 × 4,186 × (26 - T) + 76 × 387 × (26 - T)

Using a graphing calculator, we get;

83720·T + 3943000 = 62801232 - 2415432·T

The final temperature, T ≈ 23.55 °C

a transfer of energy without a transfer of mass describes what?

Answers

Explanation:

Wave motion

ex...longitudinal wave.

A truck with a mass of 15,000 kg moving at 25 m/s crashes into the back of a small 1,100 kg car moving at 15 m/s. They
stick together after the collision. Calculate the momentum of the system before the collision and after the collision.

Answers

Explanation:

Given that,

Mass of a truck = 15,000 kg

Speed of the truck = 25 m/s

Mass of car = 1,100 kg

Speed of the car = 15 m/s

As they stick together after the collision. Let V be the speed after the collision.

Initial momentum of the system,

[tex]P_i=15000\times25+1100\times15\\\\=391500\ kg-m/s[/tex]

Final momentum of the system,

[tex]P_f=(15000+1100)V\\\\=16100V[/tex]

Hence, this is the required solution.


State the relationship between the mass of trolley and acceleration of the trolley?

Answers

Answer: The complementary relationship indicated by the Newton's second law...

For a given applied force the acceleration of the trolley is inversely proportional to it's mass.

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