# Science Feedback

by Ron Kurtus

Readers have sent in a total of 4977 comments and questions on Science issues. They are listed according to date.

## List of next 15 letters

### Country

How do magnets work? Magnetism Australia

How is going to the beach scientific? Wave Motion USA

Confused about the definition of work General Pakistan

Bringing in a freezer from Manila to Australia AC World Voltages Australia

When a combination of elements is not magnetic Magnetic Factors India

What is hysteresis? Magnetic Materials India

What is Ohm's Law? Basics of Static Electricity India

Spreakers Electromagnetic Devices ??

Preventing water line from freezing Thermal Insulation USA

Which material lowers friction? Changing Sliding Friction on Hard Surfaces Pakistan

Behaviour of atoms during evaporation Kinetic Theory of Matter Namibia

Attraction or repulsion between the particles of a gas Kinetic Theory of Matter Nigeria

Using 50Hz devices on 60Hz AC World Voltages Viet Nam

How are electrons and protons affected by a current? Electromagnetism India

Can friction be applied to time? Friction Equation Canada

Next 15 letters

First 15 letters

## How do magnets work?

September 9, 2015

### Question

How do we know how magnets work?

Callum - Australia (26364)

By sprinkling iron filings near a magnet, you can see the force fields from the magnet. However, no one is really sure how the magnetic force fields push or pull on another magnet.

## How is going to the beach scientific?

August 30, 2015

### Question

Hello my teacher assigned me to do an essay on how going to the beach is scientific it's due tommorow is there any way u can describe every detail
Thank you love

Andrea - USA (26346)

Going to the beach allows you to observe the way the waves come and and break on the beach. It also shows how the water can move the sand around. Another scientific area concerns the various life-forms in the water and on the beach.

The big thing is that you can be curious and make observations, which is what science is about.

## Confused about the definition of work

August 26, 2015

### Question

I am confused about the mathematical form of work defination w=fd i think that it was wrong becase when we further elaburate it i.e w/d=f so from it we get that force is inversely proportional to displacement and e.g if we are applying force on a wall with our body then the wall will not cover any distance at that time but we are doing work on it and applying force on so why it was not covering any distance .

faraz - Pakistan (26339)

When you push on a wall, it seems like you are doing work. However, the scientific definition of work requires motion. Work is the force on an object that is resisting motion times the distance it is moved.

For example, when you push on a heavy box, it is being held back by the force of friction. You are not doing any scientific work until you are able to move that box.

## Bringing in a freezer from Manila to Australia

August 25, 2015

### Question

Bringing in a freezer from Manila to Australia. Manila uses 220v 60 Hz. Australia is 240v 50 Hz. Will this cause problems?
Thanks

Robin - Australia (26333)

It probably won't matter. However, the motor may run at a slightly different speed. It is best the check with the manufacturer to verify this.

## When a combination of elements is not magnetic

August 23, 2015

### Question

If two or more elements are chemically combined to form a molecule, it is quite possible that the compound is not very magnetic because the orientations of the atoms in the molecule work against each other.
how?

- India (26331)

Stainless steel is an example of an alloy or chemical combination of steel and chromium. Although steel by itself is magnetic, stainless steel is not because the chromium atoms prevent the iron atoms from aligning to a magnetic field.

## What is hysteresis?

August 23, 2015

### Question

EXPLAIN HYSTERESIS

- India (26332)

Hysteresis is when a ferromagnetic material is magnetized in one direction, it will not relax back to zero magnetization when the imposed magnetizing field is removed. It must be driven back to zero by a field in the opposite direction.

An example is when you magnetize a piece of iron and then remove the magnet, the iron will not relax back to zero magnetization.

## What is Ohm's Law?

August 22, 2015

### Question

What is ohm's law?

Satyavir - India (26328)

Ohm's Law shows the relationship between voltage, current, and resistance in a simple electrical circuit. The easiest form of the equation is: V = IR

See Ohm's Law for Simple Electrical Circuits.

## Spreakers

August 20, 2015

### Question

Dear Sir,
We found your company on internet and noted that you probably purchase Speaker Parts from China ( Speaker Magnet , Ferrite, Back Plate, Top Plate, Speaker Driver , Tweeter Driver, Speaker Yoke, Speaker Washer, Speaker Diaphragms, Speaker Parts...... ),so we are writing to you to see if we can help.
We are a professional manufacturer of high quality custom made Magnetic Loudspeaker Assemblies at our lowest cost in Ningbo China. You can visit our website for more details.
Do you have any new demand on the above products? We will send you the best price as soon as we receive your inquiry.
We look forward to hearing from you.
Sincerely yours,
John Hu
Ningbo Yinzhou Xiaosheng Magnetics Co., Ltd.
Add?Qianao Industrial Zone, Hengxi Town, Yinzhou Area, Ningbo 315131, China.
PH?0086-574-87157369?
FX? 0086-574-87165734;
Email: sales3@xmagnetics.com
Website: www.xmagnetics.com

John - ?? (26283)

I am sorry but this is an educational website. We do not purchase items.

## Preventing water line from freezing

August 16, 2015

### Question

hi
I am trying to prevent my water line hook up from freezing.
I have a 3' x 3' x 4' deep manhole.
The manhole cover is 2 5/8 thick Douglas fir.
I intend to put a layer of 2 inch foam insulation
and then fill the hole with 3 L plastic bottles
that are caped. then another layer of 2 inch foam insulation. Then the wood cover.
Will this insulate the pipe that is at 4feet?
A another possibility would be to put a 55 gallon plastic barrel in the hole with foam or fiberglass insulation along its sides and top. Would this work?
Or do you have a suggestion?
Thank you for the help
WH

will - USA (26278)

It seems like you certainly plan sufficient insulation for the water line in the manhole. However, it might worthwhile to check with your utility company to see what recommendations they may have. I'm sure there are others with a similar situation.

Best wishes in protecting your pipes.

## Which material lowers friction?

August 14, 2015

### Question

which of the following material lowers friction when pushed between metal plates option (a)water(b)fine marble powder(c) air(d)oil

All of them would reduce the friction between metal plates. Oil is probably the best lubricant of the group.

## Behaviour of atoms during evaporation

August 12, 2015

### Question

what is the behaviour of atoms during the evaporation phase change in terms of kinetic theory?

Wilka - Namibia (26268)

Evaporation is when the higher energy atoms escape the body of the liquid. Those atoms have enough kinetic energy to remain in the gas phase. The average energy of those atoms remaining in the liquid drops, because of the loss of high kinetic energy atoms.

## Attraction or repulsion between the particles of a gas

August 11, 2015

### Question

According to kinetic theory of matter,the force of attraction or repulsion between the particles of a gas are
a.elastic
b.large
c.small
d.strong
e.weak

Timilehin olawumi - Nigeria (26267)

Although the collisions between particles are elastic, the attraction or repulsions between particles is very weak.

## Using 50Hz devices on 60Hz

August 7, 2015

### Question

I have a question regarding the matching of voltage and frequency.

If my equipment using 220V-50Hz connected to the electric circuit of 220V-60Hz, will it create the "electrical noise"?

Should I need to match both the voltage and the frequency?

Thank you.
Quoc

Quoc - Viet Nam (26260)

If you 50Hz equipment has motors, they will slightly faster on 60Hz electricity. This is true with many clocks. However, most modern electronic equipment are usually not affected by the frequency difference.

I don't think you will be bothered by electrical noise.

## How are electrons and protons affected by a current?

August 6, 2015

### Question

How the position electrons and protons get affected when a electric current passes through a conductor.

Mohit - India (26259)

Typically, only electrons move through a conductor. However, the electric field created can move outside free electrons in one direction and free protons in the other direction.

## Can friction be applied to time?

August 4, 2015

### Question

can friction be applied to time?

Friction can slow down motion. You could say that it slows down the time it takes for an object move some distance. So it indirectly is applied to time.

However, friction cannot be applied directly to time.

## Misc

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