-3
$\begingroup$

I want to lift a weight of 1kg so how much force is required ? This is my question. Again I want to mention that 1Kg is weight not mass. I think if i say weight then gravitational pull is already acting on it.

For example if it's in earth then the multiplication factor would be 9.81m/s2. According to newton second law F=ma where m is mass not weight

W[weight] =mg = 1kg

so the value of mass m=w/g=1/9.81=0.1kg

F1=ma = 0.1 * 9.81 = 1N

So the number says 1N force is required to counteract the gravitational pull.

So total force required is completely based on my required accelecration

Lets say a= 2m/s2

F2= 0.1*2=0.2N

F=F1+F2

=1+0.2 =1.2N

So total of 2N is required to lift a weight of 1kg at 2m/s2

but I came across a lot of articles I got terribly confused between Mass and Weight. I have pasted the links for your clarification.

  1. Understanding required torque for a motor lifting a weight
  2. https://answers.yahoo.com/question/index?qid=20070514190751AABga9t

Clarify this please

$\endgroup$
8
  • 4
    $\begingroup$ "W [weight] =mg = 1kg" That is just wrong. If $m = 1$ kg and $g = 9.81$, m/s then $W$ (weight) = $1 \times 9.81 = 9.81$ Newtons. "United States customary units" are totally confusing - so don't try to understand them until you have got your thinking straightened out in SI units - and don't confuse yourself even more with hybrid monstrosities like "kilograms force". $\endgroup$
    – alephzero
    Aug 7 '17 at 19:30
  • $\begingroup$ which of the 5 clear and simple answers on the yahoo answers page don't you understand? $\endgroup$
    – agentp
    Aug 7 '17 at 20:14
  • $\begingroup$ I'll echo alephzero's comment to reinforce this - start with SI units and the dimensions they represent. Then (re)introduce the combinations of those units to derive other properties such as force, acceleration, etc... Once you're truly comfortable with the units and their combinations, then start considering values applied to the units. And stay away from Imperial units / US customary units for as long as possible. $\endgroup$
    – user16
    Aug 8 '17 at 3:00
  • $\begingroup$ @alephzero how about "poundal" ... ? :) $\endgroup$
    – Solar Mike
    Aug 8 '17 at 6:57
  • $\begingroup$ but why people are noting down my weight in Kg $\endgroup$ Aug 8 '17 at 12:03
3
$\begingroup$

Mass is measured in kg and weight measured in N.

$\endgroup$
1
  • 1
    $\begingroup$ Mass - measure quantity of matter, while Weight is a force due to gravitation. A kilogram of mass can have zero force, or 9.81N force depends on gravity (but still, it is 1 kg quantity of mass). $\endgroup$
    – RainerJ
    Aug 8 '17 at 6:51

Not the answer you're looking for? Browse other questions tagged or ask your own question.