a steel girder weighting 700 lb is hoisted from gund level to the roof of a 70-ft building using a chain that weighs 4lb/running foot. Find the work done

Answer:

here u go

Explanation:

Earth's rotation is the rotation of planet Earth around its own axis. Earth rotates eastward, in prograde motion. As viewed from the north pole star Polaris, Earth turns counterclockwise.

"Radiocarbon dating is a method for determining the age of an object containing organic material by using the properties of radiocarbon."

Answer:

well for me I think

Explanation:

The use of carbon 12 to tell the age of substances

Answer:

Explanation: The chemical action that occurs in the cell while the current is flowing causes hydrogen bubbles to form on the surface of the anode. This action is called POLARIZATION. Some hydrogen bubbles rise to the surface of the electrolyte and escape into the air, some remain on the surface of the anode. If enough bubbles remain around the anode, the bubbles form a barrier that increases internal resistance. When the internal resistance of the cell increases, the output current is decreased and the voltage of the cell also decreases.

   A cell that is heavily polarized has no useful output. There are several methods to prevent polarization or to depolarize the cell.

   One method uses a vent on the cell to permit the hydrogen to escape into the air. A disadvantage of this method is that hydrogen is not available to reform into the electrolyte during recharging. This problem is solved by adding water to the electrolyte, such as in an automobile battery. A second method is to use material that is rich in oxygen, such as manganese dioxide, which supplies free oxygen to combine with the hydrogen and form water.

   A third method is to use a material that will absorb the hydrogen, such as calcium. The calcium releases hydrogen during the charging process. All three methods remove enough hydrogen so that the cell is practically free from polarization.

LOCAL ACTION

   When the external circuit is removed, the current ceases to flow, and, theoretically, all chemical action within the cell stops. However, commercial zinc contains many impurities, such as iron, carbon, lead, and arsenic. These impurities form many small electrical cells within the zinc electrode in which current flows between the zinc and its impurities. Thus, the chemical action continues even though the cell itself is not connected to a load.

   Local action may be prevented by using pure zinc (which is not practical), by coating the zinc with mercury, or by adding a small percentage of mercury to the zinc during the manufacturing process. The treatment of the zinc with mercury is called amalgamating (mixing) the zinc. Since mercury is many times heavier than an equal volume of water, small particles of impurities weighing less than mercury will float to the surface of the mercury. The removal of these impurities from the zinc prevents local action. The mercury is not readily acted upon by the acid. When the cell is delivering current to a load, the mercury continues to act on the impurities in the zinc. This causes the impurities to leave the surface of the zinc electrode and float to the surface of the mercury. This process greatly increases the storage life of the cell.

Answer:

PLEASE MARK AS BRAINLIEST!!

Explanation:

ANSWER IS IN THE IMG BELOW

Answer:

v0 = 24.42 m/s (Approx)

Explanation:

Given:

Increase in frequency = 7.1% =

Computation:

Assume n = 100%

n1 = [(v+v0)/(v+v1)]n

[100 + 7.1] =  [(344+v0)/(344+0)]100

107.1 =   [(344+v0)/(344)]100

v0 = 24.42 m/s (Approx)

Answer:

The minimum coefficient of static friction required, µ = 0.10

Note. The question is incomplete. The complete question is given below:

While hauling a log in the back of a flatbed truck, a driver is pulled over by the state police. Although the log cannot roll sideways, the police claim that the log could have slid out the back of the truck when accelerating from rest. The driver claims that the truck could not possibly accelerate at the level needed to achieve such an effect. Regardless, the police write a ticket anyway and now the driver court date is approaching.

The log has a mass of m = 929 kg; the truck has a mass of M = 8850 kg. According to the truck manufacturer, the truck can accelerate from 0 to 55 mph in 23.0 seconds, but this does not account for the additional mass of the log. Calculate the minimum coefficient of static friction μs needed to keep the log in the back of the truck.

Explanation:

First, velocity in mph is converted to m/s

1 mph = 0.447 m/s

55 mph ≈ 24.6 m/s

The acceleration of the empty truck is a = v/t = 24.6 / 23 = 1.07 m/s²

Force that can be generated by the truck, F = ma

F = 8850kg * 1.07 m/s² = 9469.5 N

However, with the added mass of the log on it, the acceleration of the truck will become;

a = F / m = 9469.5 N / (8550+929)kg = 0.97 m/s²

Frictional force between the log and the truck = 0.97 m/s² * 929 kg = 901.13 N

Normal reaction on the truck due to the weight of the log, R = mg

R = 929 kg * 9.8m/s² = 9104.2 N

Coefficient of static friction, µ = F/R

µ = 901.13/9104.2

µ = 0.098 ≈ 0.10

Therefore, the minimum static friction required is µ = 0.10

Answer:

29.96m/s

Explanation:

Given parameters:

Initial speed  = 25.5m/s

Acceleration  = 1.94m/s²

Time  = 2.3s

Unknown:

Final speed of the car  = ?

Solution:

To solve this problem, we are going to apply the right motion equation:

    v = u  + at

v is the final speed

u is the initial speed

a is the acceleration

t is the time taken

 Now insert the parameters and solve;

      v  = 25.5 + (1.94 x 2.3)  = 29.96m/s

Answer:

6.77m/s

Explanation:

Using the law of conservation of momentum

m1u1 + m2u2 = (m1+m2)v

m1 and m2 are the masses of the object

u1 and u2 are the velocities before collision

v is the final collision

Given

m1 = 300g  = 0.3kg

u1 = 6.0m/s

m2 = 10g = 0.01kg

u2 = 30m/s

Required

The bird's speed immediately after swallowing v

Substitute the given values into the formula

m1u1 + m2u2 = (m1+m2)v

0.3(6) + 0.01(30) = (0.3+0.01)v

1.8+0.3 = 0.31v

2.1 = 0.31v

v = 2.1/0.31

v = 6.77m/s

Hence the bird's speed immediately after swallowing is 6.77m/s

Answer:

(2x + 4)(x - 4)=2x^2-4x-16

Answer: Kinetic Energy to Electrical.

Explanation: The magnet is rotated as a result of the spinning wheels, and this results in a powerful stream of electrons, therefore converting kinetic to electrical.

Answer:

the upward force is equal to the passenger weight

The answer that is the truth about the force that the seat exerts on the passenger is the upward force is equal in magnitude to the passenger's weight.

The acting forces on the body has been said to be vertical. This implies that the upward force and the downward force of gravity are the same.

Using the second law of Isaac Newton, the downward direction of the forces would be ascertained.

Read more on force and magnitude here:

https://brainly.com/question/19802988

Answer:

A thyristor (/θaɪˈrɪstər/) is a solid-state semiconductor device with four layers of alternating P- and N-type materials. It acts exclusively as a bistable switch, conducting when the gate receives a current trigger, and continuing to conduct until the voltage across the device is reversed biased, or until the voltage is removed (by some other means).

Explanation:

Correct me if im wrong

Answer:

4417

i think because

mv^2/r is centripetal force

Although the semi truck certainly has a larger mass, it is not in motion and therefore does not have any momentum. The bicycle however has both mass and velocity and therefore has the larger momentum of the pair.

Answer:

nearly 2 days or less hes fast but not that fast

Explanation:

but maybe he can run it in five minutes

Answer:

Explanation:

The average kinetic energy can be found by using the formula

[tex]k = \frac{1}{2} m {v}^{2} \\ [/tex]

m is the mass

v is the velocity

From the question we have

[tex]k = \frac{1}{2} \times 200 \times {5}^{2} \\ = 100 \times 25[/tex]

We have the final answer is

Hope this helps you

Answer:

The cantaloupe has a speed of 117.6 m/s

Explanation:

Free Fall Motion

It occurs when an object falls under the sole influence of gravity. Any object that is being acted upon solely by the force of gravity is said to be in a state of free fall. Free-falling objects do not face air resistance.

If an object is dropped from rest in a free-falling motion, it falls with a constant acceleration called the acceleration of gravity, which value is [tex]g = 9.8 m/s^2[/tex].

The final velocity of a free-falling object after a time t is given by:

vf=g.t

The cantaloupe has been dropped from rest. We are required to find the speed after t=12 seconds.

Calculate the final speed:

vf=9.8 * 12 = 117.6 m/s

The cantaloupe has a speed of 117.6 m/s

Answer:

yes

Explanation:

Answer:

a

[tex]L = 5.25*10^{7} \ m[/tex]

b

[tex]m = 1 \ kg[/tex]

c

[tex]t = 1.46112000000 *10^{11} \ s[/tex]

Explanation:

From the question we are told that

     Length  is   L  = 52500000 m

      Mass  is    

     Time  is   2435200000    minutes

Generally the proper SI for length is  meters ,

Now converting the given length to proper SI form using the appropriate prefixes we have that

             [tex]L = 5.25*10^{7} \ m[/tex]

Generally the proper SI for mass is  kilograms

converting  grams to kilograms , we have

           [tex]m =\frac{1000}{1000 }[/tex]

=>       [tex]m = 1 \ kg[/tex]

Generally the proper SI for time  is  seconds

converting  minutes  to seconds , we have

        [tex]t = 24352000000* 60[/tex]

=>      [tex]t = 146112000000 \ s[/tex]

Now converting to the  proper SI form using the appropriate prefixes

        [tex]t = 1.46112000000 *10^{11} \ s[/tex]

Answer:

7,539 m/s

Explanation:

Let's use this equation to find the gravitational acceleration of this space shuttle:

We know that G is the gravitational constant: 6.67 * 10^(-11) Nm²/kg².

M is the mass of the planet, which is Earth in this case: 5.972 * 10^24 kg.

r is the distance from the center of Earth to the space shuttle: radius of Earth (6.3781 * 10^6 m) + distance above the Earth (630 km → 630,000 m).

Plug these values into the equation:

Remove units to make the equation easier to read.

Multiply the numerator out.

Add the terms in the denominator.

Simplify this equation.

The acceleration due to gravity g = 8.11045189 m/s². Now we use the equation for acceleration for an object in circular motion which contains v and r.

a = g, v is the velocity that the space shuttle should be moving (what we are trying to solve for), and r is the radius we had in the previous equation when solving for g.

Plug these values into the equation and solve for v.

Remove units to make the equation easier to read.

Multiply both sides by 7,008,100.

Take the square root of both sides.

The shuttle should be moving at a velocity of about 7,539 m/s when it is released into the circular orbit above Earth.

Answer:

clockwise

Explanation:

According to the law given by Lenz, known as the Lenz law, it is said that a current induced in the circuit which is due to the change in the magnetic field and is so directed so as to oppose the change in the flux and to apply a force in the opposite direction if the force.

Here, as the magnetic field is directed out of the screen, the current flows in the direction which is clockwise in the loop and it opposes the increasing magnetic field.

The clockwise induced current will produce magnetic field in to the screen.

Answer:

Informal education is important because it can help individual to learn how to react and control situations.

It help individual to improve on its existing knowledge, new skills or ideas. This kind of education can happen any where and it can add values to the learner.

Explanation:

Informal education is a type of education that is learned from different life experiences, happenings outside a structured curriculum.

Informal education is important because it can help individual to learn how to react and control situations.

It help individual to improve on its existing knowledge, new skills or ideas. This kind of education can happen any where and it can add values to the learner.

Answer:the answer is “A book sitting on a high shelf” :)

Explanation:

Answer:

Refractive index of the plastic = 1.46

Explanation:

By Snell's law,

[tex]\frac{\text{sin}\theta _{2} }{\text{sin}\theta _{1}}=\frac{n_1}{n_2}[/tex]

Here, [tex]\theta _1[/tex] = Angle of incidence in medium 1 (Plastic)

[tex]\theta_2[/tex] = Angle of refraction in medium 2 (Water)

[tex]n_1[/tex] = Refractive index of medium 1 (Plastic)

[tex]n_2[/tex] = Refractive index of medium 2 (Water)

By substituting values in the formula,

[tex]\frac{\text{sin}(48.7)}{\text{sin}(55.5)}=\frac{1.33}{n_2}[/tex]

[tex]n_2=\frac{1.33\times \text{sin}(55.5)}{\text{sin}(48.7)}[/tex]

    = 1.46

Therefore, refractive index of the plastic = 1.46

Answer:

 N= 3

Explanation:

For this exercise we must use Faraday's law

          E = - dФ / dt

         Ф = B . A = B Acos θ

tje bold indicate vectors. As it indicates that the variation of the field is linear, we can approximate the derivatives

         E = - A cos θ (B - B₀) / t

The angle enters the magnetic field and the normal to the area is zero

         cos 0 = 1

         A = π r²

In the length of the wire there are N turns each with a length L₀ = 2π r

          L = N (2π r)

          r = L / 2π N

    we substitute

          A = L² / (4π N²)

The magnetic field produced by a solenoid is

           B = μ₀ N/L   I

for which

            B₀ = μ₀  N/L   I

The final field is zero, because the current is zero

            B = 0

We substitute

           E = - (L² / 4π N²)  (0 - μ₀ N/L I) / t

           E = μ₀ L I / (4π N t)

           N = μ₀ L I / (4π t E)

The electromotive force is E = 0.80 mV = 0.8 10⁻³ V

let's calculate

           N = 4π 10⁻⁷ 200 1.60 / (4π 0.120 0.8 10⁻³)]

           N  = 320 10⁻⁷ / 9.6 10⁻⁶

           N = 33.3 10⁻¹

          N= 3

Answer:

a. yes

Explanation:

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