why does trapped air in a vacuum flask reduce heat loss by conduction?

Answers

Answer 1
Having a vacuum prevents conduction from occurring completely bc there are no molecules to transfer the heat...since air is a poor conductor of heat, having trapped air in the sponge and hollow plastic stopper help prevent heat loss by conduction
Answer 2

Answer:

Explanation:

The answers are:

1) D

2) B

3) D

4) C

5) A

6) A

7) D

8) D

9) A

10) B

11) C

12) C

13) C

14) B

15) B


Related Questions

Planets, stars, asteroids and other celestial bodies have generally round shapes. Some are ovals, others really bumpy circles, and some are a very squished oval. Why are none triangular or rectangular?

Answers

planets revolve and rotate, they go around something and they spin, pretend they are on a road(orbit path) while they rotate and revolve. It's liking rolling a chunk of playdough in your hands to form a ball. same goes for asteroids, stars are auctally gases so that one I'm not sure how to answer.

if you were in a canoe on a calm lake and you threw a heavy stone into the water in front of you what would the canoe do
A- the canoe would move backward a bit

B- the canoe would move forward a bit

C- the canoe would move forward and keep going

D- the canoe would not move because it is too heavy

Answers

Answer: Option A: The canoe would move backward a bit.

Explanation:

Newton's third law of motion states that for every action there is equal and opposite reaction. This means when you threw a heavy stone in front of you, you applied a force. Equal and opposite force acted on the canoe and it moved backward a bit.

Hence, according to Newton's third law of motion, when you throw a heavy stone forward, and equal amount of force will push the canoe backwards.

Final answer:

In a canoe, throwing a heavy stone into the water away from you will cause the canoe to move backward a bit due to Newton's Third Law of Motion. This motion is equal and opposite to the force applied when throwing the stone. The principles of forces help understand canoeing strategies, as well as the motion and sinking of objects in water.

Explanation:

When you are in a canoe on a calm lake and throw a heavy stone into the water, what you're experiencing is an application of Newton's Third Law of Motion, which states that for every action, there is an equal and opposite reaction. So, if you throw the stone away from the canoe, the force of throwing the stone forward will produce a reactive force in the opposite direction, causing the canoe to move backward a bit, which corresponds with option A. This movement is temporary, and once the initial reactionary force dissipates, the canoe will stop moving backward unless other forces are at play.

Canoeing techniques also involve understanding the forces at play. When paddling a canoe upstream, staying near the shore is wise due to the slower water speeds caused by friction between the water and the riverbanks. Meanwhile, when canoeing downstream, it is often best to stay near the middle where the current is stronger and can assist in propelling you forward with less effort.

This understanding of forces also clarifies that the motion of objects, such as a stone thrown into water, can be influenced by factors like density and gravitational force, rather than only the force exerted by a throw. When a stone is placed in water, it sinks because the stone's density is greater than water's, leading to a gravitational force that exceeds the buoyant force on the object.

Which of the following make up the nucleus of an atom?

Answers

Protons and neutrons
Protons and neutrons make up the nucleus, while electrons travel around the outside.

Hope this helps!


HELP PLEASE ASAP!!!!
Which of the following terms describes how mountains form?

A: Gradually
B: Rapidly
C: Explosively
D: Destructively

Answers

I would have to say A because they happen over a period of time not all at once like the other three answers
A: Gradually. it took Mt. St Helene along time to grow.

The atomic number of magnesium is 12. This means that its nucleus must contain

A) 6 protons and 6 neutrons.
B) 6 neutrons and 6 electrons.
C) 12 neutrons and no protons.
D) 12 protons and no electrons.

Answers

The correct answer is D) 12 protons and no electrons. This is correct because the number of protons in the nucleus of the atom is 12. The number of protons in the nucleus represents the atomic number. Therefore if there are 12 protons in the nucleus, the atomic number is 12.

D took test c:

*have a great day/evening c: *

A new statue of the town founder is erected in the park.  At the unveiling, the statue is a orange-brown copper.  After a year, the statue looks blue-green.  Has a physical or chemical change taken place?

Answers

A chemical change? Is the answer to your question
A chemical change has occurred because the copper has been oxidized which is the reason for the color change. 

Describe how an electromagnet is created? What makes it attract ferromagnetic materials?

Answers

A wire that has electrical current successively over it makes a magnetic field. Actually, the simplest electromagnet is a single wire that is twisted up and has an electric current consecutively through it. The magnetic field produced by the coil of wire is like a normal bar magnet. Only definite materials, for instance iron, nickel, cobalt, and gadolinium, display strong magnetic properties. These materials are called ferromagnetic. Ferromagnetic materials will react powerfully to magnets and can also be magnetized themselves. Often an electromagnet is enclosed around a core of ferromagnetic material, for example steel, which improves the magnetic field produced by the coil.

what is the mass number of an atom with 5 protons and 7 neutrons?

Answers

Boron I think look at the periodic table
Pretty close to 12 .

Dylan is the best athlete in our school. He plays football, basketball, and baseball and does the pole vault for the track team. He can vault up to five and seventy-three hundredths meters. If he would like to be able to pole vault up to six and twelve hundredths meters, how many more centimeters does he need to pole vault to reach his goal?

Answers

We need to subtract his current status by his goal:

goal - current = needed
6.12 - 5.73 = 0.39 m.

Now, we need to convert to cm. Since there is 100 cm in 1 m:

0.39 * 100
39 cm

Hope this helps!

1. Why are the poppy seeds placed in different places (not together)?

Answers

Because they will stick.
because they were placed in different places

Discuss potential behavioral concerns for people should they travel to Mars.

Answers

on earth you calculate N by your weight times 9.8 but on Mars it's times 3.7 because there's less gravity there. Our muscles will become weaker because we wouldn't use them as often. Your heart muscle becomes weaker. And you'll probably feel alone because you just left earth with billions of people on it

The Answer above is Correct :)

our boss asks you compare two sound waves and determine which has the higher frequency. Wave A has a period of 4⁄100 second and Wave B has a perio of 1⁄7 second.

Answers

The periodic time is the inverse of frequency. This means that:
Period = 1/frequency
Therefore,
Frequency = 1/period

For wave A:
period = 4/100
frequency = 1/(4/100) = 100/4 = 25 Hz
For wave B:
period = 1/7
frequency = 1/(1/7) = 7 Hz

Based on this, wave A has higher frequency.
Wave A- period = 4/100 and the frequency = 1/(4/100) = 100/4 = 25 Hz
Wave B- period = 1/7 and the frequency = 1/(1/7) = 7 Hz

Wave A has a higher frequency.

the chart lists the masses of four balls that have the same momentum. Which correctly compares 2 of the balls

Answers

b is the correct answer

Answer:B : D

The correct answer would be B:The red ball has a greater velocity than the purple ball.

Hope this helped : )

Explanation:

An object is dropped from a building and strikes the ground with a speed of 31m/s. How tall is the building?

Answers

Final answer:

The height of the building from which an object is dropped can be calculated using the formula h = v²/(2g). Substituting the given final velocity of 31 m/s, the building's height is found to be approximately 49.03 meters.

Explanation:

Calculating the Height of the Building from Final Velocity

We can calculate the height of the building from which an object is dropped using the final velocity and the equations of motion under gravity. Assuming that air resistance is negligible and acceleration due to gravity g is constant at 9.8 m/s², the formula derived from the kinematic equations is h = v²/(2g), where h is the height, v is the final velocity, and g is the acceleration due to gravity.

Given that the final velocity is 31 m/s, we can substitute this into the formula along with the acceleration due to gravity:

h = (31 m/s)² / (2 * 9.8 m/s²) = 961 / 19.6 = 49.03 meters. Therefore, the height of the building is approximately 49.03 meters.

What did early South American civilization do to promote farming

Answers

The Incan used there many techniques to more efficiently use water.

The velocity of a wave is a function of its:

energy
form
medium
amplitude

Answers

Answer:

amplitude is the answer

What are the formulas to calculate acceleration A. velocity and time B. displacement and time C. Change in distance and time D. Change in velocity and time

Answers

Final answer:

Acceleration can be calculated using the formula for change in velocity divided by change in time. For example, if an object starts with an initial velocity of 10 m/s and ends with a final velocity of 20 m/s in a time interval of 5 seconds, the acceleration can be calculated as 2 m/s².

Explanation:

The formula to calculate acceleration is d. Change in velocity and time. Average acceleration can be found by dividing the change in velocity by the change in time. For example, if an object starts with an initial velocity of 10 m/s and ends with a final velocity of 20 m/s in a time interval of 5 seconds, the acceleration can be calculated as (20 m/s - 10 m/s) / 5 s = 2 m/s².

Which procedure would best allow a scientist to observe a chemical property of hydrochloric acid (HCl) solution? cooling the HCl solution until it becomes solid, and measuring this temperature adding zinc to the HCl solution and observing whether or not bubbles are produced placing a conductivity probe into a beaker of HCl solution to determine if it conducts electricity measuring the mass of and volume of a sample of HCl solution to find its density

Answers

Answer: Adding zinc to the HCl solution and observing whether or not bubbles are produced.

A change in property that can be observed or can be measured without changing the substance's composition chemically is known as physical property. For example, change in temperature, change in state, change in mass, volume etc.

A change in property due to change in the chemical composition of the substance is known as chemical change. for example, when two substances react with each other and a chemically different product of formed.

→cooling the HCl solution until it becomes solid, and measuring this temperature- Physical change

→placing a conductivity probe into a beaker of HCl solution to determine if it conducts electricity-Physical change

→measuring the mass of and volume of a sample of HCl solution to find its density-Physical change

→adding zinc to the HCl solution and observing whether or not bubbles are produced-Chemical change:This would allow scientists to observe chemical property of HCl solution.

Answer:

The answer is B

Explanation:

I just took the test on edge

What does the force of gravity on an object depend on?
A. the object's mass
B. compounds
C. molecules
D. charged particles

Answers

The force of gravity on an object depend on the object's mass. 
That's why the same objects will weight differently on different planets. 

all but one statement applies to electromagnetic radiation

Answers

D) Electromagnetic radiation travels in the form of longitudinal waves.

Answer:

Its D   can i get brainliest  

Explanation:

Which factors are most likely to limit the growth of the coral reef in the caribbean?

A. High rainfall and clear waters
B. Low rainfall and excessive sunlight
C. High moisture and excessive sunlight
D. Extreme temperature and cloudy waters

Answers

D. Extreme temprature and cloudy waters

The process by which planets form when material orbiting some stars starts gathering together through collision and gravitation and electrostatic attraction is called

A) accretion
B) nuclear fusion
C) differentiation
D) strong nuclear force

Answers

Answer: A) accretion

Explanation:

Accretion is the growth of a body by aggregation of matter. This is a process of accumulation of particles in a massive object gravitationally attracting more matter, typically gaseous matter, in an accretion disk.

It should be noted that this theory was proposed by Russian geophysicist Otto Schmidl in 1944 and explains that most of the objects in the universe, such as galaxies, stars and planets, are formed by accretion processes. A good example of this is the accretion of mass by a star that is given by the addition of mass to the star from interstellar matter or a neighbor star.

Please help have no clue on this

Answers

has no effect on tempature

This is an imaginary line on Earth's surface equidistant from the North Pole and South Pole that divides the Earth into a northern hemisphere and a southern hemisphere

Answers

Answer:

Equator

Explanation:

A graph of Boyle’s law shows the relationship between

A. Volume and density of gas

B. Volume and pressure of a gas

C. Temperature and volume of a gas

D. Temperature and pressure of a gas

Answers

I believe the answer might be A. Volume of density of gas

A small child gives a plastic frog a big push at the bottom of a slippery 2.0 meter long, 1.0 meter high ramp, starting it with a speed of 5.0 m/s. What is the frog's speed as it flies off the top of the ramp?

Answers

Refer to the diagram shown below.

Because the ramp is slippery, ignore dynamic friction.
Let m =  the mass of the frog.
g = 9.8 m/s²

The KE (kinetic energy) at the bottom of the ramp is
KE₁ = (1/2)*(m kg)*(5 m/s)² = 12.5 m J

Let v =  the velocity at the top of the ramp.
The KE at the top of the ramp is
KE₂ = (1/2)*m*v²= 0.5 mv² J
The PE (potential energy) at the top of the ramp relative to the bottom is
PE₂ = (m kg)*(9.8 m/s²)*(1 m) = 9.8m J

Conservation of energy requires that
KE₁ = KE₂ + PE₂
12.5m = 0.5mv² + 9.8m
0.5v² = 2.7
v = 2.324 m/s

Answer: 2.324 m/s



The Richter scale, used to measure the strength of an earthquake is _________.


A. linear

B. quadratic

C. exponential

Answers

I'm guessing it is exponential

Answer: C. Exponential

Explanation:

Your environment can play a role in whether or not a specific gene is expressed

Answers

I don't think so. How are you supposed to write the answer?
true is the answer
hope it helped!

How would you calculate the spring constant of an unknown spring?

Answers

 the spring constant k is the slope of the straight line W versus x plot.

Final answer:

To find the spring constant, apply Hooke's Law using the formula F = kx, where F is force due to gravity (mg), and x is the stretch distance. For a 10.0 kg mass stretching the spring 8.00 cm, the spring constant is calculated as 1225 N/m.

Explanation:

To calculate the spring constant (k) of a spring, you can use Hooke's Law, which is F = kx, where F is the force applied to the spring, and x is the displacement of the spring from its equilibrium position. In the scenario where a spring stretches 8.00 cm (or 0.080 meters) for a 10.0 kg load, the force exerted by the load (F) can be found using the force due to gravity, which is F = mg. The mass (m) is 10.0 kg, and the acceleration due to gravity (g) is approximately 9.80 m/s². Thus, F = (10.0 kg) × (9.80 m/s²) = 98.0 newtons (N).

Now that we know F and x, we can solve for the spring constant (k):

k = F/x

k = 98.0 N / 0.080 m

The spring constant k is 1225 N/m.

IIn what form does the sun energy arrive on earth

Answers

Hey I believe that the answer is either Radiation or Convection. If I’m wrong then I am srry but from what I have heard it is probably Convection.I believe that the answer is either Convection or Radiation. But from what I have head it is Probably Convection. Hope I helped.

Answer:

radiation

Explanation:

This is because sun energy travels in form of waves and thus doesn't require a medium to travel in

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