Work - Science lesson

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I use this powerpoint to teach work to my science students.

I use this powerpoint to teach work to my science students.

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  • 1. Calculating Work
    • To calculate work
    • Work = force x distance
    • W = F x d
  • 2. Example
    • A teacher applies a force of 50N to move a students bag 10m. How much work is done?
    • W = Fxd
    • W = 50 x 10
    • W = 500J
  • 3. Work (energy)
    • The amount of energy being used is called WORK.
    • It is measured in units called joule, symbol J
    • Work = Force used x distance moved
    • (In joules) = (in newtons) (in metres)
    Aim - to find out how much work it is to lift weights Example - Steve bench presses 100Kg a distance of 0.5m How much work has he done
  • 4. 100Kg = a weight force of 1000N so ….. Work = 1000 x 0.5 = 500 joules Now try the problems below . 1 Kevin lifts 150 kg in a clean and jerk, a distance of 2m. How much work has he done? 2 Stephanie curls 40kg a distance of 0.2 m. How much work has she done? 3 Steven military presses 80Kg a distance of 0.5m. He does this five times. How much work has he done? 4 Rob side lifts a 15Kg dumbbell 0.3m. He does this 30 times. How much work has he done?
  • 5. 1 Kevin lifts 150 kg in a clean and jerk, a distance of 2m. How much work has he done? Weight = 150Kg x 10N/Kg = 1500N Work = Force x distance = 1500N x 2m = 3000 Joules = 3 kJ 2 Stephanie curls 40kg a distance of 0.2 m. How much work has she done? Weight = 40Kg x 10N/Kg = 400N Work = Force x distance = 400N x 0.2m = 80 Joules
  • 6. 3 Steven military presses 80Kg a distance of 0.5m. He does this five times. How much work has he done? Weight = 80Kg x 10N/Kg = 800N Work = Force x distance = 800N x 0.5m = 400 Joules x 5 = 2,000 joules = 2 kJ 4 Rob side lifts a 15Kg dumbbell 0.3m. He does this 30 times. How much work has he done? Weight = 15Kg x 10N/Kg = 150N Work = Force x distance = 150N x 0.3m = 45 Joules x 30 times = 1,350 Joules = 1.35 kJ
  • 7. Problem 1 Work = Force x distance
  • 8. Problem 2
  • 9. Problem 3
  • 10. Problem 4
  • 11. Answers
    • W = F x d
    • 1 1750 x 2 = 3500 J
    • 2 5000 x 10 = 50000J
    • 3 1000 x 15 = 15000 J
    • 4 10000 x 2 = 20000J