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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 91 · 40 questions
TalentJR

Robot tip (Teeth × turns): Teeth passing = driver teeth × driver turns. Driven turns = teeth passing ÷ driven teeth. Gear ratio = driven teeth ÷ driver teeth (a ratio of 3 means 3 times slower).

NameDateTime takenScore ___ / 40
  1. 1.⚙️ A motor makes 210 turns a minute with a 12-tooth gear on it. That gear drives a 36-tooth gear. How many turns a minute does the 36-tooth gear make?
  2. 2.⚙️ A 10-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  3. 3.🔢 To climb a steep ramp, a robot needs a gear ratio that is … (a) never important (b) big (slow and strong) (c) small (fast, weak) (d) zero
  4. 4.⚙️ A 20-tooth driver gear turns an 80-tooth driven gear. The driven gear turns 3 times. How many times did the driver turn?
  5. 5.⚙️ A 12-tooth driver gear turns a 36-tooth driven gear. The driver turns 21 times. How many times does the driven gear turn?
  6. 6.⚙️ A 24-tooth driver gear turns a 12-tooth driven gear. The driver turns 7 times. How many times does the driven gear turn?
  7. 7.⚙️ A motor makes 200 turns a minute with an 8-tooth gear on it. That gear drives a 16-tooth gear. How many turns a minute does the 16-tooth gear make?
  8. 8.🔢 Gear ratio = driven teeth ÷ … (a) wheel size (b) number of gears (c) driver teeth (d) motor volts
  9. 9.⚙️ A motor makes 40 turns a minute with a 12-tooth gear on it. That gear drives a 48-tooth gear. How many turns a minute does the 48-tooth gear make?
  10. 10.⚙️ An 8-tooth driver gear turns a 40-tooth driven gear. The driven gear turns 10 times. How many times did the driver turn?
  11. 11.⚙️ A 100-tooth driver gear turns a 20-tooth driven gear. The driver turns 10 times. How many times does the driven gear turn?
  12. 12.⚙️ A 12-tooth gear drives a 24-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  13. 13.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?
  14. 14.⚙️ A 15-tooth gear drives a 45-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  15. 15.⚙️ An 8-tooth driver gear turns a 24-tooth driven gear. The driver turns 18 times. How many times does the driven gear turn?
  16. 16.⚙️ A motor makes 220 turns a minute with an 8-tooth gear on it. That gear drives a 16-tooth gear. How many turns a minute does the 16-tooth gear make?
  17. 17.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driver turns 20 times. How many times does the driven gear turn?
  18. 18.⚙️ A motor makes 240 turns a minute with a 15-tooth gear on it. That gear drives a 45-tooth gear. How many turns a minute does the 45-tooth gear make?
  19. 19.⚙️ A 20-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  20. 20.⚙️ An 8-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  21. 21.⚙️ A 12-tooth driver gear turns a 36-tooth driven gear. The driver turns 27 times. How many times does the driven gear turn?
  22. 22.⚙️ A motor makes 30 turns a minute with an 8-tooth gear on it. That gear drives a 24-tooth gear. How many turns a minute does the 24-tooth gear make?
  23. 23.⚙️ A 20-tooth gear drives a 60-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  24. 24.⚙️ A 40-tooth driver gear turns a 20-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?
  25. 25.⚙️ A 20-tooth gear drives a 40-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  26. 26.⚙️ A motor makes 500 turns a minute with an 8-tooth gear on it. That gear drives a 40-tooth gear. How many turns a minute does the 40-tooth gear make?
  27. 27.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driver turns 12 times. How many times does the driven gear turn?
  28. 28.⚙️ A 20-tooth driver gear turns an 80-tooth driven gear. The driver turns 12 times. How many times does the driven gear turn?
  29. 29.⚙️ A 15-tooth driver gear turns a 30-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  30. 30.⚙️ A 100-tooth driver gear turns a 20-tooth driven gear. The driver turns 1 time. How many times does the driven gear turn?
  31. 31.⚙️ An 8-tooth gear drives a 32-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  32. 32.⚙️ An 8-tooth gear drives a 16-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  33. 33.🔢 A gear ratio of 3 (driven ÷ driver) means the driven gear turns … (a) 3 times slower (b) 3 times bigger (c) 3 times faster (d) 3 times louder
  34. 34.⚙️ A 40-tooth driver gear turns an 8-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  35. 35.⚙️ A 12-tooth gear drives a 60-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  36. 36.⚙️ A 12-tooth driver gear turns a 60-tooth driven gear. The driven gear turns 5 times. How many times did the driver turn?
  37. 37.⚙️ A 15-tooth driver gear turns a 45-tooth driven gear. The driver turns 15 times. How many times does the driven gear turn?
  38. 38.⚙️ A 12-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  39. 39.⚙️ A 12-tooth driver gear turns a 36-tooth driven gear. The driven gear turns 7 times. How many times did the driver turn?
  40. 40.⚙️ A 30-tooth driver gear turns a 10-tooth driven gear. The driver turns 5 times. How many times does the driven gear turn?

Answer key

  1. 70
  2. 30
  3. big (slow and strong)
  4. 12
  5. 7
  6. 14
  7. 100
  8. driver teeth
  9. 10
  10. 50
  11. 50
  12. 2
  13. 1
  14. 3
  15. 6
  16. 110
  17. 5
  18. 80
  19. 60
  20. 16
  21. 9
  22. 10
  23. 3
  24. 8
  25. 2
  26. 100
  27. 3
  28. 3
  29. 3
  30. 5
  31. 4
  32. 2
  33. 3 times slower
  34. 30
  35. 5
  36. 25
  37. 5
  38. 24
  39. 21
  40. 15

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