Ask you all a science question...

• banzie

  10 Apr 07, 19:54

  Let say a weight is 1000kg Then it is hang by a string what is the force required to pull the weight from a pendulum
  
  Basically means it is tied to a string how much force you need to pull it from the side. I know to pull it up is 1000kg by what about 90 degree to the side leh?
  
  Issit 500kg? or what?
• Darkness_hacker99

  10 Apr 07, 19:58

  maybe he can help you..
  
  Hamiltonian1125
  
• Ito_^

  10 Apr 07, 20:08

  its magic.
• tek_koh

  10 Apr 07, 20:12

  i tink i learn b4..but forget liao paiseh
• alan-

  10 Apr 07, 20:16

  ask your sec school physics teacher
• LinkageII

  10 Apr 07, 20:38

  if you take all other factors to be negligible (friction etc), the load will move even if you apply a very small force from the side.. but it gets complicated after that.. so yeah
• blahshit

  10 Apr 07, 20:47

  Originally posted by banzie:

  Let say a weight is 1000kg Then it is hang by a string what is the force required to pull the weight from a pendulum
  
  Basically means it is tied to a string how much force you need to pull it from the side. I know to pull it up is 1000kg by what about 90 degree to the side leh?
  
  Issit 500kg? or what?

  ouh.. to the side ah.. i dun think 500 leh.. it's base on the friction... btw, y ur force unit use kg 1? i thought use N??
• banzie

  10 Apr 07, 20:50

  Originally posted by blahshit:

  ouh.. to the side ah.. i dun think 500 leh.. it's base on the friction... btw, y ur force unit use kg 1? i thought use N??

  N is the same as KG what...
  
  Ok let say KN so how much KN to swing to the left?
• ^tamago^

  10 Apr 07, 20:50

  need centripetal?
• banzie

  10 Apr 07, 20:51

  Originally posted by blahshit:

  ouh.. to the side ah.. i dun think 500 leh.. it's base on the friction... btw, y ur force unit use kg 1? i thought use N??

• blahshit

  10 Apr 07, 20:56

  Originally posted by banzie:

  N is the same as KG what...
  
  Ok let say KN so how much KN to swing to the left?

  ???swing to the left??? wat toking u?? btw, ur previous qn, that's not a full qn leh... u haven't give me the friction force.. and the pulling up 1 also wrong.. it's not 1000... cause gt gravity acting on it.. need more force..
• LinkageII

  10 Apr 07, 21:01

  if the load weighs say.. 100N, assuming other factors are negligible, you'll need (100+a small amount of force)N upwards to actually lift it. 100N will not allow you to lift it upwards
• snop_coolz

  10 Apr 07, 21:10

  u take the vertical distance from ur weight to ur pivoted point multiply it by 1000 and u get the amount of force need...no its not 500..depends on ur distance..and to lift it up u simply need to have a 1001N
• blahshit

  10 Apr 07, 21:14

  -delete-
• blahshit

  10 Apr 07, 21:26

  Originally posted by banzie:

  Let say a weight is 1000kg Then it is hang by a string what is the force required to pull the weight from a pendulum
  
  Basically means it is tied to a string how much force you need to pull it from the side. I know to pull it up is 1000kg by what about 90 degree to the side leh?
  
  Issit 500kg? or what?

  ouh wait.. i think i know the answer..
  
  since F=ma,
  
  F=1000xa(gravity)
  F=1000x10
  F=10000N
  
  (this is for lifting up horizontally)
  
  then pull across the floor..
  it's the same..
  
  no friction and no acceration
  F=ma
  F=1000x0
  F=0N
  
  if got friction and acceration the formula will be..
  F-f=ma
  
  lets say the friction is 15N and acceration is 0.5m/s
  
  then it will be
  
  F-15N=1000x0.5
  F=500+15
  F=515N
  
  understand?
  
• banzie

  10 Apr 07, 21:34

  Not lifting up
  
  I mean swing to the side.
• blahshit

  10 Apr 07, 21:36

  Originally posted by banzie:

  Not lifting up
  
  I mean swing to the side.

  swing like a pendulum???
• banzie

  10 Apr 07, 21:45

  yea
  
  Like example you have a girl on a swing. which is 50 kg how much force you need to pull her to the back so she can swing?
• hatemeifuwantto

  10 Apr 07, 21:47

  i think the force needed is the same as the force of the thing
• blahshit

  10 Apr 07, 21:51

  Originally posted by banzie:

  yea
  
  Like example you have a girl on a swing. which is 50 kg how much force you need to pull her to the back so she can swing?

  how long the swing? from the sitting thing to the top..
• blahshit

  10 Apr 07, 21:53

  do u know kinectic energy and potential energy??
  
  kinectic=1/2mv(square)
  potential=mgh
• banzie

  10 Apr 07, 21:53

  let say errm 1meter
  
  but hey need to ask so meh? Roughly how much I can expect?
• monoslayer

  10 Apr 07, 21:55

  no need force. jus use viagra. voila~
• blahshit

  10 Apr 07, 22:10

  like that?
  
  or
  
  
  
  if it's the 1st 1, i think i have given u the answer.. but if 2nd 1, i not very sure.. think 2nd 1 need to jus potential and kinectic energy thingy...
• le cruz

  10 Apr 07, 22:35

  If
  
  Fa = force exerted from side of pendulum
  Fb = tension in string
  G = gravitational force
  @ = angle between vertical datum and string
  
  Fb cos @ = G
  Fb sin @ = Fa
  
  Fa = G sin @ / cos @ = G tan @
  
  Plot Fa = G tan @ for @ = 0° to 90°