Question

Torques and levers in everyday life..

I need examples.. of this to teach.. everyday examples... the ones i know are

door handle, spanner to nut a bolt (lever)
trebuchets and rowing of boat (as speed multipliers), pedals of bicycles, scissors, hand crank machines :D
anything else?

Answer 1

can opener, crowbar

Answer 2

yah - and bottle openers, too. ummm.... door hinges are also good as torque examples - it's impossible to open a door by pushing only on its hinges but really easy if you push a ways away from the axis of rotation.

Answer 3

can openers.. yea.. totally forgot about them
And yea i already covered the door :P

Answer 4

Teeter-totters, too (those things on playgrounds)

Answer 5

U mean see saw?

Answer 6

hmm i got some more,
chopsticks :D

Answer 7

nodding of head .. lever..
that must be a speed multiplier right?

Answer 8

Action on a car's steering wheel.

Do you need to distinguish pure torques vs moment?
In that case door knob vs door handle is a good example.

Also pure torque: action of Earth magnetic field on compass needle.

Answer 9

hey steering wheel is nice
no.. infact.. there is nothing about levers or anything in the syllabus.. but thats so unfair.. when u learn torques.. its a must that u understand about so many day to day devices.. that work on the principle of torques

so i just need force multipliers and speed multipliers..

wheel is i believe a force multiplier
i got TAP.. which is also force multiplier..

also .. i never understood the difference between moments and torques.. i believe they are the same .. torque = moment of a force right?

Answer 10

They are often used as synonyms in problems.
But, it can be necessary to distinguish them. In that case:

(Pure) torque is any combination of actions that results is zero net force and non-zero moment.
In that case, the moment is called 'torque' and is independent of the point about which you express it, unlike a standard moment, that changes with the reference point.

Answer 11

so pure torque is basically what we call as a couple?

Answer 12

or wait.. couple is one special case of pure torque :D?

Answer 13

Well, I thought the word 'couple' did not exist in English :-(
Then you are right: 'couple' is pure torque or pure moment and zero net force.

Answer 14

Have to go.

Answer 15

oki.. thanks for that :) :) :)!!.