Experiment:Lifting weights using pulleys

////Experiment:Lifting weights using pulleys

Experiment:Lifting weights using pulleys

Testing pulleys using a test meter

Testing pulleys using a test meter

ZIMSEC O Level Combined Science Notes: Experiment:Lifting weights using pulleys

Aim: To use pulleys to lift loads

Materials:  4 single pulleys, string, 1kg mass/a tin filled with sand, spring balance, clamp stand, meter rule

Method

  1. Set up a fixed pulley as shown above
  2. Place a 1kg (about 1 Newton) load on one end of the spring
  3. Use a spring balance/force meter to find the effort required to lift the load
  4. Set up a  single movable pulley
  5. Determine the force required to lift the 1 kg load
  6. Set up a block and tackle pulley using a single movable pulley and a fixed pulley as shown above
  7. Determine the force required to lift the 1 kg load
  8. Set up two fixed pulleys and two movable pulleys as shown above
  9. Determine the effort required to lift the movable load

Observation and Results

Pulley systemLoadEffortMechanical Advantage
Single fixed10 NJust over 10 NJust below 1
Single movable10 NJust over 5 NJust under 2
One fixed and One Movable10 NJust over 5 NJust under 2
Two fixed and Two movable10 NJust over 2.5 NJust under 4
  • The Mechanical Advantage is below the expected figure due to friction and
  • Where applicable the blocks below the fixed pulleys
Pulley systemDistance moved by loadDistance moved by effortVelocity Ratio
Single fixed15 cm15 cm1
Single movable15 cm30 cm2
One movable and One fixed15 cm30 cm2
Two fixed and Two movable15 cm60 cm4
  • In simple terms the M.A and V.R of pulleys is equal to the number of movable pulleys multiplied by two

Conclusion

  • Fixed pulleys change the direction of force without impacting on Mechanical Advantage or Velocity Ratio
  • They make it convenient to move the load
  • Movable pulleys have a Mechanical Advantage and Velocity Ratio of 2

To access more topics go to the Combined Science Notes page

By |2017-01-17T11:11:59+00:00July 8th, 2016|Notes, O Level Science Notes, Ordinary Level Notes|Comments Off on Experiment:Lifting weights using pulleys

About the Author:

He holds an Honours in Accountancy degree from the University of Zimbabwe. He is passionate about technology and its practical application in today's world.
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