Wikipedia:Reference desk/Archives/Miscellaneous/2013 September 1

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September 1[edit]

newton's third law[edit]

Normally, when we lift any object, we apply force.Then according to newton's third law it should also apply equal force so, it should not lift, then why are we able to lift it? — Preceding unsigned comment added by 223.196.237.160 (talk) 09:36, 1 September 2013 (UTC)[reply]

The equal force isn't applied to the object, but rather to your hands as you lift it. If not for that force (it's weight), the object would seem to be weightless. StuRat (talk) 10:07, 1 September 2013 (UTC)[reply]
Say you go outside and pick up a rock. The opposite force from the rock is applied not only to you, but also the Earth on which you stand. The rock rises a few feet, whereas you and the Earth move in the opposite direction a teeeeeeny bit. Clarityfiend (talk) 11:31, 1 September 2013 (UTC)[reply]
This is explained in Newton's laws of motion#Newton's third law. There are many different phrasings for the law. I learnt it in the form: "Action and reaction are equal and opposite (and they act on different bodies)." Try holding out your rock at arm's length for a while, and you will notice the force that it exerts. Dbfirs 11:55, 1 September 2013 (UTC)[reply]
Every action has an equal and opposite reaction, but not every force is exactly balanced: if they were, nothing would change direction or speed. You are muddling actions and forces. The forces on an object are balanced only if and always when the object is at rest or travelling at a constant velocity. When you pick something up, you are applying a greater force up than the object's force-due-to-gravity is applying down. The equal and opposite reaction to your pushing the object up, is that object pushing you (and the earth beneath your feet) down, both of which actions serve to move the object and the earth further apart. The standard thought experiment is an astronaut throwing tools in the opposite direction to the way he wants to move, to get back to his spaceship on a spacewalk gone wrong. 86.163.2.116 (talk) 12:11, 1 September 2013 (UTC)[reply]
Yes, good point. It's only as you first pick the rock up that your upwards force on the rock exceeds its weight. Your upwards force on the rock is always exactly balanced by the rock's force downwards on your hand (by Newton's third law). Once you get the rock moving upwards at constant speed, all three forces are equal, but your upwards force on the rock reduces to less than its weight (just for a short time) as you stop raising the rock, then it is equal again as you hold the rock steady. Dbfirs 12:32, 1 September 2013 (UTC)[reply]

vat[edit]

i am looking for the uk vat number of the bradford and bingley plc — Preceding unsigned comment added by 86.128.98.196 (talk) 14:32, 1 September 2013 (UTC)[reply]

This PDF shows (at the bottom of the first page) the VAT number to be 287371034. Note that the date on the document is July 2010 - it is possible that the company now uses a different VAT registration number, although I note that the Company Number is the same (3938288 - confirmed here). I've been unable to find a current source for the VAT number. However, I suggest that if you need this information for something important that you contact them yourself - the company should be able to provide such details. - Cucumber Mike (talk) 16:44, 1 September 2013 (UTC)[reply]
Complex and large businesses can have multiple VAT numbers, with each unit (what HMRC calls a "body corporate") having their own. So you might find that B&B's retail banking has a different VAT number to B&B's insurance division, their merchant banking division, their private banking division, etc. You might also find that various businesses that B&B bought, that trade under the B&B umbrella, retain their old numbers. There is no substitute for asking the specific part of B&B with which you dealt for their correct, current VAT number. -- Finlay McWalterTalk 17:10, 1 September 2013 (UTC)[reply]