1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
True [87]
3 years ago
11

Which statement describes the relationship between bond strength and the melting and boiling points of a substance? A. As the fo

rce between the particles increases, the melting and boiling points also increase. O B. As the force between the particles increases, the melting point decreases and the boiling point increases. O C. As the force between the particles increases, the melting and boiling points decrease. O D. As the force between the particles increases, the melting point increases and the boiling point decreases. SUBMIT​
Physics
1 answer:
icang [17]3 years ago
4 0

Answer:

a

Explanation:

You might be interested in
Determine the power that needs to besupplied by the fanifthe desired velocity is 0.05 m3/s and the cross-sectional area is 20 cm
Mariulka [41]

Answer:

A fan with an energy efficiency of 30 % would need 62.5 watts to bring a desired volume flow of 0.05 cubic meters per second through a cross-sectional area of 20 square centimeters.

Explanation:

Complete statement is: <em>Determine the power that needs to besupplied by the fan if the desired velocity is 0.05 cubic meters per second and the cross-sectional area is 20 square centimeters.</em>

From Thermodynamics and Fluid Mechanics we know that fans are devices that work at steady state which accelerate gases (i.e. air) with no changes in pressure. In this case, mechanical rotation energy is transformed into kinetic energy. If we include losses due to mechanical friction, the Principle of Energy Conservation presents the following equation:

\eta\cdot \dot W = \dot K

\dot W = \frac{\dot K}{\eta} (Eq. 1)

Where:

\eta - Efficiency of fan, dimensionless.

\dot W - Electric power supplied fan, measured in watts.

\dot K - Rate of change of kinetic energy of air in time, measured in watts.

From definition of kinetic energy, the equation above is now expanded:

\dot W = \frac{\rho_{a}\cdot \dot V}{2\cdot \eta}\cdot \left(\frac{\dot V}{A_{s}} \right)^{2} (Eq. 2)

Where:

\rho_{a} - Density of air, measured in kilograms per cubic meter.

\dot V - Volume flow, measured in cubic meters per second.

A_{s} - Cross-sectional area of fan, measured in square meters.

If we know that \rho_{a} = 1.20\,\frac{kg}{m^{3}}, \dot V = 0.05\,\frac{m^{3}}{s}, \eta = 0.3 and A_{s} = 20\times 10^{-4}\,m^{2}, the power needed to be supplied by the fan is:

\dot K = \left[\frac{\left(1.20\,\frac{kg}{m^{3}} \right)\cdot \left(0.05\,\frac{m^{3}}{s} \right)}{2\cdot (0.3)} \right]\cdot \left(\frac{0.05\,\frac{m^{3}}{s} }{20\times 10^{-4}\,m^{2}} \right)^{2}

\dot K = 62.5\,W

A fan with an energy efficiency of 30 % would need 62.5 watts to bring a desired volume flow of 0.05 cubic meters per second through a cross-sectional area of 20 square centimeters.

5 0
3 years ago
How is air temperature related to high and low pressure air
vitfil [10]

Answer: So, I looked at it to see what was the correct one, and the correct answer is Cool air near surface forms high-pressure areas, warm air forms low pressure areas. I hope this helps :D :)

Explanation:

3 0
3 years ago
How can you describe the motion of an object in a race?
Hitman42 [59]
You can describe the motion of an object by its position, speed, direction, and acceleration
4 0
3 years ago
Which type of electromagnetic waves make up the colors of a rainbow seen after a storm?
coldgirl [10]

Answer:

we conclude that visible light is that electromagnetic wave that makes up the colors of a rainbow seen after a storm.

Hence, option A is correct.

Explanation:

Generally, after the storm, we can witness the presence of a rainbow with our naked eyes. Rainbow, visible to our eyes, consists of all the seven constituent colors of white light. Those seven colors range from violet to red, all having different wavelengths. When water particles present in our atmosphere get exposed to light, all the constituent colors of a white light tend to deviate at a variety of angles. It happens due to their refraction through water particles; thus, a spectrum is obtained.

As we cannot see X-rays, UV rays, and infrared waves through our naked eye, visible light is the kind of electromagnetic wave that makes anyone able to see the objects.  

Please note that all the constitute colors of a beautiful rainbow associate with the visible region of the electromagnetic spectrum.

Therefore, we conclude that visible light is that electromagnetic wave that makes up the colors of a rainbow seen after a storm.

Hence, option A is correct.

3 0
3 years ago
Read 2 more answers
Stars are held together by the force ___, ___ and the composition determine the amount of ___.
Alexus [3.1K]
A star is a large ball of gas that generates its own energy by fusing hydrogen atoms to make helium. It is held together by its own gravity. ... Stars come in a variety of sizes and compositions, which determine their amount of energy and gravity.
4 0
3 years ago
Other questions:
  • Between 1911 and 1990, the top of the leaning bell tower at Pisa, Italy, moved toward the south at an average rate of 1.2 mm/y.T
    13·1 answer
  • A car traveling east at 46.8 m/s passes a trooper hiding at the roadside. the driver uniformly reduces his speed to 25.0 m/s in
    11·1 answer
  • A baseball of mass 0.25 kg is hit at home plate with a speed of 40 m/s. When it lands in a seat in the left-field bleachers a ho
    15·1 answer
  • An automobile fuel tank is filled to the brim with 45 L of gasoline (12 gal) at 10°C. Immediately afterward, the vehicle is park
    7·1 answer
  • Can someone please help me​
    14·1 answer
  • Which of the following has the greatest momentum?
    6·1 answer
  • What happens to an object's gravitational potential energy as it falls from some height?​
    12·1 answer
  • (d) What type of transformation is done by the following things?
    7·1 answer
  • A car travels straight for 20 miles on a road that is 30° north of east. What is the east component of the car’s displacement
    10·1 answer
  • A spring has a spring constant of 5N/cm. What is its extension when loaded with 15N?
    9·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!