I just dropped my cordless phone, it hit a pint glass and smashed it.

My question….WTF ❓

Huh?

You can break a glass with a feather you know.

The glass wouldn’t have smashed if it had been full.

It was full of water, which pished all over my cyrus 2 and seems to have borked it 😡

Are you Dom Joly?

… it hit a pint glass and smashed it.

I’d keep that cordless phone under control Al – it could be a kid’s face next time.

You can break a glass with a feather you know

Only if it attached to a swan. They can break arms. Imagine what they could do to a child’s face.

/edit bollocks!!!! too slow 😀

http://www.britannica.com/EBchecked/topic/148758/Cyrus-II

What?

Not shitting you friends.

I was knelt down, phone sandwiched twixt ear and shoulder, it slipped out and fell a whole 18″ onto the glass and smashed the fecker.

I thought glass was harder than plastic? Or must there have been a grain of sand on the phone?

Glass is brittle. Why is it a surprise?

🙄

serious understanding fail

Hardness and being brittle are not the same thing. Glass is hard but brittle, plastic need not be either.

Is this not a good opportunity to upgrade your amp ?

Though looking at it the case is not the same as newer models.

zomg eleventyone.

I have a Yamaha KX-V595 going a-begging for a nominal fee if you’d like to replace it with a sick to the power of rad AV amp.

That amp has a sad look about it – I can’t figure out why – it’s just looking a bit sad out of that photo 🙁

Yes, i just don’t understand it! My hammer, made of ice, smashed when i was knocking in some steel nails. I thought it would be more robust given that a big lump of ice knacked the Titanic. Maybe the hammer wasn’t cold enough.

A ham sandwich dropped from the top of the Empire State building can flatten a Hummvee; fact.

A ham sandwich dropped from the top of the Empire State building can flatten a Hummvee; fact.

Yeah, but not a true one?

Kinetic energy of a ham sandwich dropping from the empire state is about the same as an average person jumping as high as they can. They must be making weak hummers these days!

I thought glass was harder than plastic?

It is, but that’s not how it works. If you were talking about if one could scratch the other – then that’s hardness.

The falling phone has energy. Some or all of that energy will be transferred to the glass in a particular direction. The impact of that energy will set shockwaves going through the glass. If the shockwaves are ‘strong’ enough then the glass won’t be able to flex enough and the glass will break. Glass doesn’t flex much which is why we call it brittle, and it’s easy to break.

If you put a pint glass upside down on a table you could probably tap it on the bottom with a hammer and it’d be ok. Put it on its side and tap the rim with a hammer – smash.

I huess I did and still do struggle with a 150gm soft plastic phone having enough energy & hardness/lack of damping to break the glass which itself would have been damped by teh water held in it.

Charlie and TJ: full marks for hating!

Al:

brittleness is just a lack of toughness, glass is brittle.

hardness and brittleness usually go together.

(examples: porcelain is hard, and brittle. iron is soft and tough, so is andrex)

your phone was obviously tough enough to withstand the impact, the glass obviously wasn’t.

As one of the many qualified materials engineers on here, I consider it my duty to respond to this thread and can give you a simple pointer as to what may have happened. Just consider this:

You can cut glass, stone or metal with water, which is softer than poo.

I nuderstand it guys, it just strikes me as odd. Looking at the glass, I think it was scratched orr maybe even cracked beforehand…

Remember you can break a glass with a human voice (just about)

you can cut glass, stone or metal with poo, it just depends on the pressure you apply. 😉

Was the glass scratched or had any stress raisers? Glass barely deforms plastically, so all impact energy is given to fracture (assuming the glass is on a hard surface and not moving). The glass you have been drinking out of is full of defects (from manufacture and usage) so it does not match the theoretical critical stress intensity, and as a result, it is pretty easy to break.

I nuderstand it guys, it just strikes me as odd

Al I’ve just re-read the thread, and looking at all your comments including this one, I realise now that this happened because you are special.

Take it as a sign , incredible things will happen to you and incredible things will happen because of you.

Also, compressive and tensile stresses etc etc.

You’ll have experienced a combination of the low ductility/ brittleness and the poor tensile strength of glass there sir.

I pretend to be a materials engineer sometimes. Forgotten most of it now though.

Where did the phone hit the glass?

In his living room.

Revert to iPod?

You need to consider the section of the glass also. It probably deflected at the point of impact causing the failure.

A solid cube of glass of the same mass but with a different section would have remained unscathed… and your amp would still be working.

Also, compressive and tensile stresses etc etc.

And shock wave constructive interference.

As we’re moving away from materials to mechanics…

How do you work out the section modulus for a shaft with irregular sized and positioned grooves in it? Shaft is a supporting object, not rotating.

Work out the grooves then subtract them from the body taking into consideration the distance from the neutral axis?

It works for I, but not for Z.

Somebody in the office needs to know and I’m not being much help despite the fancy job title and letters after my name.

I graduated in ’92 and haven’t used my brain since. 😳

Fnar fnar @ Cougar.

🙄 Hate? Dear me!
It’s not all about you.

Do something other than flame me then 🙄

Are you serious? Surely you’d just click on my forum activity before writing something so self-centred!

your phone was obviously tough enough to withstand the impact

And designed to be able to withstand small impacts too I would assume.