What is lever ?Which class of lever has mechanical advantage always more than 1 ?

Question

What is lever ?Which class of lever has mechanical advantage always more than 1 ?

Answer 1

Looks like you got two different answers.

A lever is a simple tool.

A first class lever is one with a fulcrum between the load and force.

A second class lever is one where the fulcrum is on the end but the force is further away from the fulcrum and it always has a mechanical advantage more than one.

The third class lever is one where the fulcrum is on the end again but now the force is between the load and the fulcrum, so it has a mechanical advantage below one.

Answer 2

a lever is the simplest form of a machine used to simplyfy a job

a lever of 3rd order always has a ma >1

Answer 3

A lever is a rod which rotates about a point on it called fulcrum, and can be used as a simple machine to do work easily and efficiently.

2nd class has Mechanical Advantage>1

Answer 4

lever is simple tool....

force                           weight

   ↓                                 ↓

-----------------╥-------------------

<-- l1 --------><------ l2 ------>

the principle behind this is balance of torque....

which is

t1 = force * l1

t2 = weight * l2

if l1 > l2 then with lower force, weight can be balanced.. which is an advantage...

you can refer to :

http://library.thinkquest.org/J002079F/l...