What is velocity ratio? It is impossible to get a perfect machine in practical life, why?
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Answer:

Copper is a better heat conductor than glass. In general, we think of metals as good conductors. In fact, metals vary widely in their conductivity but, overall, they are better conductors of heat than most liquids and gasses. Other solids also vary in their capability to conduct heat.

Explanation:

The best thermal insulator is glass. The correct option is D.

The prevention of heat transfer between surfaces that are in thermal contact or within a radiative influence zone is known as thermal insulation.

In addition to using the right item forms and materials, specially engineered technologies or processes can also be used to provide thermal insulation.

The term "thermal insulation" refers to the various ways we try to prevent heat from transferring from one object to another.

These two items could be the inside and outside of exterior walls in residential structures or the hot and cold faces of processing equipment in industrial settings.

Glass has a very small amount of unpaired electrons that are not in use, making it a good electrical insulator. Extremely strong electron interactions hold the atoms of glass together.

Thus, the correct option is D.

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Answer:

B) The nail has become a temporary magnet, while the bar magnet remains a permanent magnet.

Explanation:

I hope this helped you ;)

Answer:

t = 0.553

Explanation:

The mass has nothing to do with an object falling.

Givens

d = 1.5 m

a = 9.8

vi = 0

t = ?

Formula

d = vi * t + 1/2 a t^2

Solution

1.5 = 0 + 1/2 9.81 * t^2

1.5 = 4.905 t^2

1.5/4.905 = t^2

0.3058 = t^2

sqrt(t^2) = sqrt(0.3058)

t = 0.553

About 1/2 a second which is really surprising wouldn't you think?

Answer:

Current, I = 0.000109 Amps

Explanation:

Given the following data;

Voltage = 6V

Resistance = 55,000 Ohms

To find the current flowing through the circuit;

Ohm's law states that at constant temperature, the current flowing in an electrical circuit is directly proportional to the voltage applied across the two points and inversely proportional to the resistance in the electrical circuit.

Mathematically, Ohm's law is given by the formula;

[tex] V = IR[/tex]

Where;

V represents voltage measured in voltage.

I represents current measured in amperes.

R represents resistance measured in ohms.

Making current the subject of formula, we have;

[tex] I = \frac {V}{R} [/tex]

Substituting into the formula, we have;

[tex] I = \frac {6}{55000} [/tex]

Current, I = 0.000109 Amps

Answer:

polar covalent bonding

Explanation:

Water (H2O) is polar because of the bent shape of the molecule. The shape means most of the negative charge from the oxygen on side of the molecule and the positive charge of the hydrogen atoms is on the other side of the molecule. This is an example of polar covalent chemical bonding.

Answer:

Smallest - B

Largest - C

Middle - A

The hanging mass provides the force for accelerating the system.

In case A the force M G accelerates 2 * M

So you have for F = M a     M * g = 2 * M * a    or  a = g / 2

In case B  F = M a         M * g = 3 * M * a        and a = g / 3

In case C   F = 2 * M * g      2 M * g = 3 * M * a      and a = 2 * g / 3      

Rank from smallest to largest force Smallest - B, Middle - A, Largest - C.

A force is an effect that can alter an object's motion according to physics. An object with mass can change its velocity, or accelerate, as a result of a force. An obvious way to describe force is as a push or a pull. A force is a vector quantity since it has both magnitude and direction.

Smallest - B

Largest - C

Middle - A

The hanging mass provides the force for accelerating the system.

In case A the force M G accelerates 2 * M

So you have for F = M a     M * g = 2 * M * a    or  a = g / 2

In case B  F = M a         M * g = 3 * M * a        and a = g / 3

In case C   F = 2 * M * g      2 M * g = 3 * M * a      and a = 2 * g / 3  

Rank from smallest to largest force Smallest - B, Middle - A, Largest - C.

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Answer:

71344 J

Explanation:

From the law of conservation of energy,

Mechanical Energy = Kinetic Energy + Potential Energy

M.E = (mv²/2)+ mgh.................... Equation 1

Where M.E = Mechanical Energy, m = mass, v = Velocity, h = height, g = acceleration due to gravity.

Given: m = 52 kg, v = 28 m/s, h = 100 m (half way down the ski jump)

Constant: g = 9.8 m/s²

Substitute these values into equation 1

M.E = (52×28²/2) + (52×100×9.8)

M.E = 20384+50960

M.E = 71344 J

Answer:

phares

[tex]phares \\ \\ means \: a \: noun \: \\ \\ i \: thnk \: so \: \:[/tex]

It's a distinct stage in a process of change or dev't

Answer:

a the number of particles

Explanation:

the volume will decrease because the particles are closer

if the particles are closer they generate more heat and thus can change their state of matter

Answer:

The incorrect part of the chart is;

Line 1

Chemical [tex]{}[/tex] Reaction   [tex]{}[/tex]                                   Nuclear Reaction

Line 1 Happens in the nucleus of atoms   [tex]{}[/tex] Happens between atoms

Explanation:

The given chart can be presented as follows;

  Chemical Reaction [tex]{}[/tex]                               Nuclear Reaction

1. Happens in the nucleus of atoms    [tex]{}[/tex]   Happens Between atoms

2. Forms new compounds [tex]{}[/tex]                     Forms new atoms

3. Involves small amounts of energy [tex]{}[/tex]    Involves large amounts of energy

From the above chart, line 1 is incorrect because a chemical reaction happens between the valence electrons of the reacting atoms while a nuclear reaction is the reaction that takes place between the nucleus of two or more atoms or the nucleus of an atom and a subatomic particle to produce one or more than new nuclide of a new atom with a change in the mass of the nucleus being represented by the large amount of energy in the reaction. Therefore, a nuclear reaction takes place in the nucleus of an atom, forms new atoms and involves large amounts of energy

The correct arrangement is presented as follows;

  Chemical Reaction [tex]{}[/tex]                              Nuclear Reaction

1. Happens Between atoms    [tex]{}[/tex]                Happens in the nucleus of atoms

Answer:

lightning KILLUAAAA

Answer:

(b) 490 N downwards

Explanation:

(b) Formula : w= mg

m is the mass of the object

g is a gravitational constant (9.8)

w= mg

= 50×9.8

= 490 N downwards

Answer:

soory but i cant under stand it proper can explain

Answer:

7.22×10¹⁰ J

Explanation:

From the question given above, the following data were obtained:

Velocity (v) = 7.6 Km/s

Mass (m) = 2500 kg

Energy (E) =?

Next, we shall convert 7.6 Km/s to m/s. This can be obtained as follow:

1 km/s = 10³ m/s

Therefore,

7.6 Km/s = 7.6 Km/s × 10³ m/s / 1 km/s

7.6 Km/s = 7.6×10³ m/s

Finally, we shall determine the energy required as follow:

Velocity (v) = 7.6×10³ m/s

Mass (m) = 2500 kg

Energy (E) =?

E = ½mv²

E = ½ × 2500 × (7.6×10³)²

E = 1250 × 57760000

E = 7.22×10¹⁰ J

Thus, 7.22×10¹⁰ J of energy is required.

Answer:

vector of zero magnitude

Explanation:

The displacement is a vector magnitude, therefore, in addition to being a module, it has direction and sense.

In this case it moved 350 m and then returned the same 350 m, so the total displacement is zero.

If we draw the vector, one has a directional direction to the right and the other direction to the left, therefore when adding the two vectors gives a vector of zero magnitude

Answer:

go for a walk/run

pace while texting/calling someone

park further away

take the stairs instead of the elevator

get up and get something frequently, or move between rooms frequently

Answer:

Epicenter

Explanation:

The epicenter is the location of tectonic plate movement where an earthquake begins.

Answer:

The correct option is (b).

Explanation:

The ideal gas law is given by :

[tex]PV=nRT[/tex]

Where

P, V and T are pressure, volume and temperature of the gas

R is gas constant

[tex]V=\dfrac{nRT}{P}[/tex]

If n,R and P are constant,

[tex]V\propto T[/tex]

i.e.

At constant pressure, the volume of a gas is directly proportional to its temperature. Hence, the correct option is (b).

Answer:

A motion produced by electric charge which causes attractive and repulsive forces between objects.

Answer:

C. Changes mechanical energy to electrical

Answer:

A,C and D

Explanation:

Answer:

K= 95.4 J

Explanation:

For this exercise we must use the conservation of mechanical energy.

We set a reference system on the floor.

Starting point. Higher

          Em₀ = U = m g h

Final point. Just before taking the floor

           Em_f = K = ½ m v²

energy is conserved because there is no friction

         Em₀ = Em_f

         mg h = K

The height is

                 h = 0- y₀

let's calculate

       K =  3.23 (-9.81)  (-3.01)          

       K= 95.4 J

Answer:

A sonar device sends pulses of sound waves down through the water. When these pulses hit objects like fish, vegetation or the bottom, they are reflected back to the surface. The sonar device measures how long it takes for the sound wave to travel down, hit an object and then bounce back up.

25

Explanation:

P1V1=P2V2 hence 50×30=60v

V=1500÷60

V=25

Explanation:

The potential energy is stronger at the start of the bounce and when it is near the end bounce the balls accelerated rate will be lower because the force has decreased . Also I love your profile picture miraculous rocks !

Answer:

4

Explanation:

Velocity ratio is the ratio of distance moved by effort to the ratio of distance moved by load

Velocity ratio = Distance moved by effort / Distance moved by load

Distance moved by effort = 20m

Distance moved by load = 5m

20m / 5m = 4

Answer:

When a substance burns, it produces new substances during a chemical change. Therefore, whether or not a substance is flammable is a chemical property. Knowing which substances are flammable helps you to use them safely. Another chemical property is how compounds react to light

Answer:

I need to talk to somone about my confusing love life

Explanation: