Question

are class 1 levers 100% frictionless and 100% efficient ? if not , tell any device which is 100% frictionless ...... need detailed explanation !

Answer 1

it is an imaginary device not in real

Answer 2

Class 1 levers are not 100% frictionless. We can't achieve 100% frictionless in any machine. We can reduce the friction by applying lubricants like oil, grease etc. The amount of friction that can be reduced depends on the type of lubricant we are using. No matter which lubricant we use, we can't make a joint 100% frictionless.

There is no device which is 100% frictionless. We assume the joints or surfaces to be 100% frictionless to make the calculation easy. in reality, nothing is 100% frictionless.