Use of lubricants increase efficency of machine​

Answer:

C -) The friction between an object and air.

Explanation:

The frictional force is the force that exists between two surfaces in contact, which is opposed to the movement.

That is, this type of force exists as long as there is physical contact between surfaces.

While the other types of force always act at a separation distance between bodies.

a= 1156× 6.13= 7086.28

Explanation:

a = m× m/ s^2

Answer: [tex]_8^{15}\textrm{O}\rightarrow _{7}^{15}\textrm{N}+_{+1}^0{e}[/tex]

Explanation:

Positron emission: In this process, in which a proton inside a radionuclide nucleus is converted into a neutron while releasing a positron and an electron neutrino. The beta positive particle released is basically a positron with +1 charge and no mass.

General representation of an element is given as:  

[tex]_Z^A\textrm{X}\rightarrow _{Z+1}^A\textrm{Y}+_{+1}^0{e}[/tex]

where,

Z represents Atomic number

A represents Mass number

X and Y represents the symbol of an element

For [tex]_8^{15}\textrm{O}\rightarrow _{7}^{15}\textrm{N}+_{+1}^0{e}[/tex]

Answer:

a. the average kinetic energy of hydrogen atoms is  1.20 × 10^-19J

b. the average kinetic energy of helium atoms is 1.24 × 10^-17J

Explanation:

The computation is shown below;

As we know that

Kinetic energy = 3 ÷ 2 kT

where,

K = Boltzmann constant

And, T = Temperature

a. Now the temperature in kelvin is

T = (5,500 × (°C ÷ K) + 273.15 K)

= 5773.15 K

As

Kinetic energy = 3 ÷ 2 kT

So now 1.38 × 10^-23 J/K for K would be substituted and 5773.15 K for Temperature T

Now Kinetic energy is

= 3 ÷ 2 (1.38 × 10^-23 J/K) ( 5773.15 K)

= 1.20 × 10^-19J

hence, the average kinetic energy of hydrogen atoms is  1.20 × 10^-19J

b. As

Kinetic energy = 3 ÷ 2 kT

now 1.38 × 10^-23 J/K for K would be substituted and 6 × 10^5K for Temperature T

Now Kinetic energy is

= 3 ÷ 2 (1.38 × 10^-23 J/K) (6 × 10^5K )

= 1.24 × 10^-17J

hence, the average kinetic energy of helium atoms is 1.24 × 10^-17J

Answer:

1200cm²

Explanation:

Width= 30cm

Length= 40cm

Area of base(A) = Width×Length

= 30cm×40cm

= 1200cm²

Taking into account the definition of reactanguar prism and area of rectangle, the area of its base is 1200 cm².

A rectangular prism is a polyhedron whose surface is formed by two equal and parallel rectangles called bases and by four lateral faces that are also parallel and equal rectangles two by two.

So, the base being a rectangle, its area is calculated as the multiplication between the base and the height. In this case, these values ​​correspond to the width and length of the figure.

Then, in this case, you know:

Being:

Area of base (A) = Width×Length

Then, the are of base (A) is calculated as:

Area of base (A)= 30cm×40cm

Solving:

Area of base (A)= 1200cm²

Finally, the area of its base is 1200 cm².

Learn more:

Answer:

.

Explanation:

Answer:

The science of the conversions between heat and other forms of energy is thermodynamics.

Hope it helps :)

Answer:

thermodynamic is the branch of physics that deals with the  relationship between heat and  other forms of energy .it describes  how thermal energy is converted to  other forms  and how it will affect matter.

Explanation:

Answer: 6.022×10²³ molecules of CH4 which consists of 1 mole of C atoms and 4 moles of H atoms.

Answer: 44.76 kg

Explanation: There are two options for formulas to use here.

0=(m1)(V1f)+(m2)(V2f)

Or

(m1)(V1f) = —(m2)(V2f)

Both formulas should give you an answer of 44.763514, which can be rounded to the specifications of whatever your curriculum or teacher wants. Most likely 44.76.

Blessings to all of you in the Name of Jesus Christ our Savior!

Answer:

B. Atoms and their electrons are rearranged.

D. The elements stay the same.

Answer:

A longitudinal wave is a wave where the displacement of the medium is in the same direction than the propagation of the wave.

This means that as a P wave travels through the Earth, the relative motion between the p wave and the particles is near zero, as the motion of the particles is parallel to the motion of the wave.

An example of this would be the waves generated when you throw a rock in water, you can see how the water particles move along the waves in the water.

The relative motion between the p wave and the particles is almost negligible.

Learn more:

https://brainly.com/question/26095273

Answer:

You and your buddy are scuba diving and notice that air bubbles triple in volume as they rise to the surface from where you are in the ocean. Ignoring any temperature changes, how far below the surface of the water (in m) are you when these bubbles are released? The ocean has a density of 1034 kg/m3

Answer:

3.88 × 10^-4 m

Explanation:

Given that a  person who weighs 614 N is riding a 85-N mountain bike. Suppose the entire weight of the rider plus bike is supported equally by the two tires. If the gauge pressure in each tire is 9.00 x 10^5 Pa. What is the area of contact between each tire and the ground?

The total weight = 614 + 85

The total weight = 699N

Let the total area of contact = A

Pressure = Force / A

Substitute all the parameters into the formula

900000 = 699 /A

A = 699 / 900000

A = 7.77 × 10^-4 m

The area of contact between each tire and the ground will be = A/2

That is, 7.77 / 2 = 3.88 × 10^-4 m

Therefore, the area of contact between each tire and the ground is 3.88 × 10^-4 m approximately.

Answer:

Explanation:

the lowest points of a transverse wave are called the troughs what is the wavelength of a wave traveling through a rope if the distance from one crest to the next is 1 meter a. 2 m

4. Low points are called troughs

5. Medium: substance through which a wave can travel

Answer:The answer is when a metal plate is pressed against a fast spinning piece of steel hard enough to stop it. i know this because I just took a test and got this question and got it write

Explanation:

Answer:

The frequency heard by the observer is 24,830.35 Hz.

Explanation:

Given;

frequency of the source, Fs = 18,002 Hz

speed of the source, Vs = 130

speed of sound in air, V = 343 m/s

Apply Doppler effect, as the source and the observer move closer to each other, the frequency heard by the observer increases because of decrease in distance.

[tex]f_s = f_o[\frac{v}{v + v_s} ]\\\\[/tex]

where;

f₀ is the frequency heard by the observer

[tex]f_s = f_o[\frac{v}{v + v_s} ]\\\\18,002 = f_o[\frac{343}{343 + 130} ]\\\\18,002 = f_o(0.725)\\\\f_o = \frac{18,002}{0.725} \\\\f_o = 24,830.35 \ Hz[/tex]

Therefore, the frequency heard by the observer is 24,830.35 Hz.

Answer:

108.33 grams.

Explanation:

Given that,

Mass of a egg, m = 65 g

Volume of an egg, V = 60 cc

We need to find the mass of the salt dissolved in 100cc of water so that egg just float in water.

The density will remains constant,

[tex]\dfrac{m_1}{V_1}=\dfrac{m_2}{V_2}\\\\m_2=\dfrac{m_1V_2}{V_1}\\\\m_2=\dfrac{65\times 100}{60}\\\\=108.33\ g[/tex]

So, the required mass is 108.33 grams.

Answer:

0.159

Explanation:

Given that

F1 = 440 N

F2 = 340 N

m = 500 kg

acceleration, a = 0 m/s²

Remember that F = m.a

If F - f(f) = 0, then F = f(f)

N = mg

f(f) = μN, substituting for N, we have

f(f) = μmg

The total force, F = F1 + F2

F = 440 + 340

F = 780 N

Recall that we'd already proven that

F = f(f), so F = 780 N = f(f)

And again, f(f) = μmg, if we substitute for all the values, we have

780 = μ * 500 * 9.81

780 = μ * 4905

μ = 780 / 4905

μ = 0.159

Therefore, the coefficient of static friction of the crate on the floor is 0.159

Answer:

The thermal energy is carried by electromagnetic waves

Explanation:

There are three types of transfer of heat (thermal energy):

- Conduction: conduction occurs when two objects/two substances are in contact with each other. The heat is transferred from the hotter object to the colder object by the collisions between the molecules of the two mediums.

- Convection: convection occurs when a fluid is heated by an external source of heat. The part of the fluid closer to the heat source gets warmer, therefore it becomes less dense and it rises, and it is replaced by the colder part of the fluid, which is colder. Then, this part of fluid is heated as well, so it gets warmer, it rises, etc.. in a cycle.

- Radiation: radiation occurs when thermal energy is carried by electromagnetic waves. Since electromagnetic waves do not need a medium to propagate, this is the only method of heat transfer that can occur through a vacuum (so, in space as well).

Indeed, the Sun emits a lot of electromagnetic radiation, which travels through space and eventually reaches the Earth, heating it.

Explanation:

The required average speed of bicycle rider is 12 km/h.

Given data:

The distance travelled by the bicycle rider is, d = 15 km.

Time taken to cover the distance is, t = 1.25 h.

Here, we need to use the simple relation between the speed, time and distance. The distance covered covered by any object per unit of time is known as average speed of object. And the mathematical expression for the average speed is given as,

[tex]v = \dfrac{d}{t}[/tex]

Here, v is the average speed.

Solving as,

[tex]v = \dfrac{15}{1.25}\\\\v = 12\;\rm km/h[/tex]

Thus, we can conclude that the required average speed of bicycle rider is 12 km/h.

Learn more about the average speed here:

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Answer:

0.37 m

Explanation:

Let the shoulder be the origin.

The center of mass of the arm bones is 0.60 m/2 = 0.30 m and the center of mass of the hand bones is 0.10 m/2 = 0.05 m since they are modeled as straight rods with uniform density and the center of mass of a rod is x = L/2 where L is the length of the rod.

The center of mass y = (m₁y₁ + m₂y₂)/(m₁ + m₂) where m₁ = mass of arm bones = 4.0 kg, y₁ = distance center of mass of arm bones  from shoulder = 0.30 m, m₂ = mass of hand bones = 1.0 kg and y₂ = distance of center of mass hand bones from shoulder = x₁ + distance of center of hand bones from wrist = 0.60 m + 0.05 m = 0.65 m

Substituting these into the equation for the center of mass, we have

y = (m₁y₁ + m₂y₂)/(m₁ + m₂)

y = (4.0 kg × 0.30 m + 1.0 kg × 0.65 m)/(4.0 kg + 1.0 kg)

y = (1.20 kgm + 0.65 kgm)/5.0 kg

y = 1.85 kgm/5.0 kg

y =  0.37 m

The distance of the center of mass from the shoulder is thus y = 0.37 m

They could determine it by counting their total amount of miles mark went by the directions he went to walk those miles.

Given :

A spring with a spring constant of 1730 N/m is compressed 0.136 m from its equilibrium position with an object having a mass of 1.72 kg.

To Find :

The embankment in the height.

Solution :

Since no external force is acting in the system, therefore total energy will be conserved.

Initial kinetic energy of the object = Energy stored in spring

[tex]K.E _i = \dfrac{kx^2}{2}\\\\K.E_i = \dfrac{1730\times 0.136^2}{2}\\\\K.E_i = 16\ J[/tex]

Also, initial potential energy is 0.

Now,

[tex]K.E_i + P.E_i = K.E_f + P.E_f\\\\16 + 0 = \dfrac{1.72\times 2.45^2}{2}+ mgh\\\\mgh =16 - 5.16\\\\h = \dfrac{16 - 5.16}{1.72 \times 9.8}\\\\h = 0.64\ m[/tex]

Therefore, the embankment height is 0.64 m.

Answer: 9.3m/s

Explanation:

Your question isn't complete but let me help out:

A 0.060 kg ball hits the ground with a speed of –32 m/s. The ball is in contact with the ground for 45 milliseconds and the ground exerts a +55 N force on the ball. What is the magnitude of the velocity after it hits the ground?

We would use Newton's law of motion to solve this which goes thus:

F = ma

f = m(v-u)/t

Cross multiply

ft = m(v-u)

where,

f = 55

t = 45/1000 = 0.045

m = 0.0060

u = -32

v = Unknown

Therefore,

55 × 45/1000 = 0.060(v - -32)

55 × 0.045 = 0.060(v + 32)

2.475 = 0.06(v + 32)

2.475 = 0.06v + 1.92

0.06v = 2.475 - 1.92

0.06v = 0.555

v = 0.555/0.06

v = 9.25m/s

v = 9.3m/s Approximately

Answer:

A.9.3 m/s

Explanation:

Answer:

Explanation:

This image is the example of Newton's first law of motion because:

As per Newton's first law, football will remain in the state of rest until a player applies an external force by kicking the ball.

And the ball will keep on moving until unless the net of a goal post exerts the external force to stop the ball.

Answer:

The value is [tex]N = 1.107 *10^{45 } \ photons[/tex]    

Explanation:

From the question we are told that

   The  power output from the sun is  [tex]P_o = 4 * 10^{26} \ W[/tex]

   The average wavelength of each photon is  [tex]\lambda = 550 \ nm = 550 *10^{-9} \ m[/tex]

Generally the energy of each photon emitted is mathematically represented as

        [tex]E_c = \frac{h * c }{ \lambda }[/tex]

Here  h is the Plank's constant with value  [tex]h = 6.62607015 * 10^{-34} J \cdot s[/tex]

          c is the speed of light with value  [tex]c = 3.0 *10^{8} \ m/s[/tex]

So

       [tex]E_c = \frac{6.62607015 * 10^{-34} * 3.0 *10^{8} }{ 550 *10^{-9} }[/tex]          

=>   [tex]E_c = 3.614 *10^{-19} \ J[/tex]          

Generally the  number of photons emitted by the Sun in a second is mathematically represented as

         [tex]N = \frac{P }{E_c}[/tex]

=>      [tex]N = \frac{4 * 10^{26} }{3.614 *10^{-19}}[/tex]

=>      [tex]N = 1.107 *10^{45 } \ photons[/tex]    

Answer: no because you have left the number

Explanation: