Contractions
Submitted: Monday, Jun 07, 2010 at 09:12
ThreadID:
79136
Views:
2821
Replies:
6
FollowUps:
9
This Thread has been Archived
Member - Doug T (NT)
No....not the having a baby type of contractions , I always believed that things expanded when they they warm up and contract when cold, so here's one for you to ponder on, We have a
young Brahman calf wandering about and to keep it away from the van I tied my Snatch Strap tightly across the front between two uprights of the shed, what I have noticed is in the morning when it's cccold (17deg) it has expanded and gone quite slack, when it warms up it goes tight again...WHY.
Do your own test and see.
.
Reply By: Member - Kingsley N (SA) - Monday, Jun 07, 2010 at 10:01
Monday, Jun 07, 2010 at 10:01
Moisture, Doug. Just like guy ropes etc.
Kingo
AnswerID:
419892
Follow Up By: Member - Doug T (NT) - Monday, Jun 07, 2010 at 10:05
Monday, Jun 07, 2010 at 10:05
You think so, we don't get all that much dew here, in fact it felt dry, and I know I went to the toilet .....lol
FollowupID:
690070
Follow Up By: Gramps - Monday, Jun 07, 2010 at 14:29
Monday, Jun 07, 2010 at 14:29
Maybe the brahman has worked it out. Cunning beasties those brahmans :)))
Regards
FollowupID:
690096
Follow Up By: Member -Dodger - Monday, Jun 07, 2010 at 15:41
Monday, Jun 07, 2010 at 15:41
I like the Brahma cattle theory LOL.
FollowupID:
690102
Follow Up By: Member No 1- Tuesday, Jun 08, 2010 at 07:50
Tuesday, Jun 08, 2010 at 07:50
given same amount of water... a teaspoon full...when evaporated into a given amount of air.....
a warmer temperature can hold more water, meaning that with a given amount of moisture we end up with less humidity or drier air
now if we have same amount of water evaporated into a cooler air temp gives a higher humidity or the air can hold less water...
so even though it felt dry it would be at a higher humidity
I think thats right.....where's my pshychrometric chart
FollowupID:
690165
Reply By: Alloy c/t - Monday, Jun 07, 2010 at 14:46
Monday, Jun 07, 2010 at 14:46
When did u put the strap inplace ? Tin shed roof expands during the day ,ergo if you put the strap tightly inplace during the heat of the day the strap is extended , come cooler morning tin roof has contracted and strap is slack.
AnswerID:
419919
Follow Up By: rags - Monday, Jun 07, 2010 at 15:43
Monday, Jun 07, 2010 at 15:43
Are you sure it has nothing to do with the earths rotation and when we are upside down that the strap will stretch !or should that be when we are upside down the strap is loose! don't ask me where is Dr Karl when we need him
FollowupID:
690103
Follow Up By: Member - Doug T (NT) - Monday, Jun 07, 2010 at 17:49
Monday, Jun 07, 2010 at 17:49
Alloy
I put it there during daylight hours, as tou can see it is now tight, in the morning the center will be half way down to the ground, there's no way the roof could have any effect ,
Image Could Not Be Found
.
FollowupID:
690117
Reply By: Rob! - Monday, Jun 07, 2010 at 15:57
Monday, Jun 07, 2010 at 15:57
moisture, or to be more precise - relative humidity.
AnswerID:
419929
Reply By: Member - Doug T (NT) - Monday, Jun 07, 2010 at 17:58
Monday, Jun 07, 2010 at 17:58
I just took a measurment of the distance between the uprights while it's tight, will re measure again when it's slack.
.
AnswerID:
419950
Reply By: The Explorer - Monday, Jun 07, 2010 at 19:18
Monday, Jun 07, 2010 at 19:18
Hello
Not 100% sure how a snatch strap is constructed but rubber with elastic characteristics (e.g. elastic band) shrinks when heated and expands when cooled (including changes in elasticity). This appears to be exactly what you are observing.
Cheers
Greg
| I sent one final shout after him to stick to the track, to which he replied “All right,” That was the last ever seen of Gibson - E Giles 23 April 1874 Lifetime Member
My Profile My Blog My Position Send Message
Moderator |
AnswerID:
419958
Follow Up By: The Explorer - Monday, Jun 07, 2010 at 19:19
Monday, Jun 07, 2010 at 19:19
PS - nothing to do with moisture
| I sent one final shout after him to stick to the track, to which he replied “All right,” That was the last ever seen of Gibson - E Giles 23 April 1874 Lifetime Member
My Profile My Blog My Position Send Message
Moderator |
FollowupID:
690121
Follow Up By: The Explorer - Monday, Jun 07, 2010 at 20:58
Monday, Jun 07, 2010 at 20:58
...or the shed
| I sent one final shout after him to stick to the track, to which he replied “All right,” That was the last ever seen of Gibson - E Giles 23 April 1874 Lifetime Member
My Profile My Blog My Position Send Message
Moderator |
FollowupID:
690139
Follow Up By: Member - Doug T (NT) - Monday, Jun 07, 2010 at 22:55
Monday, Jun 07, 2010 at 22:55
Greg
I think you'd have to be on the ball, the strap at 10:15pm is slack, the distance between uprights is unaltered,
.
FollowupID:
690149
Reply By: cycadcenter - Tuesday, Jun 08, 2010 at 05:25
Tuesday, Jun 08, 2010 at 05:25
The "little people" came in from the scrub and borrowed it and when they returned it they couldn't pull it up tight.
Keep and eye out for their little footprints.
Bruce
AnswerID:
420001