Australia's Science Forum

Hi Everyone
Just wondering if anyone has any ideas that may help me out. One of the physics teachers wants to test time of flight. She wants to roll a ball down a ramp to the end of the desk then let it fall from the desk to the ground.She will get the take off points and landing points but wants to time how it takes to fall from the desk to the floor.
I'm stumped,
Krysia

Sounds like a data logger set-up to me. Use motion sensors and the data logger does the rest!

Thanks Rosalie
We tried that and she wasn't happy with it. Not sure why.
Krysia

The only other alternative I can think of is to set up a strobe light and use photography like we did in the "good ol' days"...

this sounds to me like a job for the students to be doing in class,not the Labbie!
The teacher should be getting the students to do this as part of the prac.

Have a look in Physics store for block of wood thingy with metak cross piece and two steel balls in side of wood
You twist the metal bit till it's across block place a ball on each side and release trigger the cross piece propels ball out and swings out from under the other ball both balls hit ground together but one travelled a lot further in an arc while the other dropped straight down
both drop at 9.81 metres per second squared due to gravity but one ball also had a lateral force which propeled it sideways at the same time
I is that clear?

As mud!!!!!!

But intriguing!

I have done a similar thing using a Video camera. Just prop a metre rule up against the bench and roll the ball off the desk and film it as it goes down. They can either look up how many frames per second the video camera takes, or determine this themselves by filming a stop watch for a few seconds. You just need a video player that will let you advance one frame at a time, but any computer video editing software will do that.

Cheers
Ian

this sounds like a job for MYTHBUSTERS!!

then of coarse, they will have to blow it up when they finish!

Right Oh! so I'm not a poet, but open yer lugs What I was Describing is to be found in Serrata Catalogue bottom of page 48 of 58 Physics section item No 1014004
Falling bodies apparatus (Newtons 2nd law)

Hey Ocker,

I knew what you meant! I have one of those bizzos. And yeah, videos work well.

Hey thanks everyone,
I'm going for the video idea with the stopwatch and frames/sec.
You're all so helpful, witty, intelligent etc etc etc etc.
Krysia

Hey Ocker,
Couldn't quite picture the equipment mentally from your description. Found a picture of the falling bodies apparatus on the net and it looks exactly as you described. I haven't come across this piece of equipment in our collection. How relevant and useful would it be to have this specific piece of equipment available for Physics?
Lyn.

P.S. I know that may be a dumb question but I really would like to upgrade some of our Physics equipment and sometimes it is difficult to pin the Physics teachers down as to what they require.

It's pretty basic, but also indestructable, except for lost balls and at a price of 20 bucks, what have you got to lose?