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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 63 · 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.🔢 To climb a steep ramp, a robot needs a gear ratio that is … (a) small (fast, weak) (b) zero (c) big (slow and strong) (d) never important
  2. 2.⚙️ A 20-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  3. 3.⚙️ A 12-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  4. 4.🔢 A gear ratio of 3 (driven ÷ driver) means the driven gear turns … (a) 3 times louder (b) 3 times faster (c) 3 times bigger (d) 3 times slower
  5. 5.⚙️ A motor makes 240 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?
  6. 6.⚙️ A motor makes 120 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?
  7. 7.⚙️ A 20-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  8. 8.⚙️ A 10-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  9. 9.⚙️ A 10-tooth driver gear turns a 40-tooth driven gear. The driven gear turns 2 times. How many times did the driver turn?
  10. 10.⚙️ A motor makes 60 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?
  11. 11.⚙️ An 8-tooth gear drives a 24-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  12. 12.⚙️ A 10-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  13. 13.⚙️ A 24-tooth driver gear turns an 8-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  14. 14.⚙️ A 20-tooth gear drives an 80-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  15. 15.⚙️ A 20-tooth driver gear turns a 60-tooth driven gear. The driver turns 18 times. How many times does the driven gear turn?
  16. 16.⚙️ An 8-tooth driver gear turns a 16-tooth driven gear. The driven gear turns 6 times. How many times did the driver turn?
  17. 17.⚙️ A 20-tooth driver gear turns a 100-tooth driven gear. The driven gear turns 9 times. How many times did the driver turn?
  18. 18.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driven gear turns 4 times. How many times did the driver turn?
  19. 19.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driver turns 20 times. How many times does the driven gear turn?
  20. 20.⚙️ A 20-tooth driver gear turns a 40-tooth driven gear. The driver turns 16 times. How many times does the driven gear turn?
  21. 21.🔢 Gear ratio = driven teeth ÷ … (a) number of gears (b) wheel size (c) driver teeth (d) motor volts
  22. 22.⚙️ A 20-tooth gear drives a 60-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  23. 23.⚙️ A motor makes 200 turns a minute with a 15-tooth gear on it. That gear drives a 30-tooth gear. How many turns a minute does the 30-tooth gear make?
  24. 24.⚙️ A 10-tooth driver gear turns a 30-tooth driven gear. The driven gear turns 10 times. How many times did the driver turn?
  25. 25.⚙️ A 12-tooth driver gear turns a 36-tooth driven gear. The driven gear turns 9 times. How many times did the driver turn?
  26. 26.⚙️ A motor makes 180 turns a minute with a 10-tooth gear on it. That gear drives a 30-tooth gear. How many turns a minute does the 30-tooth gear make?
  27. 27.⚙️ A motor makes 100 turns a minute with a 15-tooth gear on it. That gear drives a 75-tooth gear. How many turns a minute does the 75-tooth gear make?
  28. 28.⚙️ A motor makes 40 turns a minute with a 12-tooth gear on it. That gear drives a 24-tooth gear. How many turns a minute does the 24-tooth gear make?
  29. 29.⚙️ A 32-tooth driver gear turns an 8-tooth driven gear. The driver turns 7 times. How many times does the driven gear turn?
  30. 30.⚙️ A 15-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  31. 31.⚙️ A 15-tooth driver gear turns a 75-tooth driven gear. The driver turns 40 times. How many times does the driven gear turn?
  32. 32.⚙️ A 20-tooth driver gear turns a 100-tooth driven gear. The driver turns 30 times. How many times does the driven gear turn?
  33. 33.⚙️ A 20-tooth driver gear turns a 40-tooth driven gear. The driven gear turns 2 times. How many times did the driver turn?
  34. 34.⚙️ A 60-tooth driver gear turns a 12-tooth driven gear. The driver turns 8 times. How many times does the driven gear turn?
  35. 35.⚙️ A 10-tooth driver gear turns a 50-tooth driven gear. The driver turns 20 times. How many times does the driven gear turn?
  36. 36.⚙️ A 12-tooth gear drives a 60-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  37. 37.⚙️ A motor makes 90 turns a minute with a 20-tooth gear on it. That gear drives a 60-tooth gear. How many turns a minute does the 60-tooth gear make?
  38. 38.⚙️ A 15-tooth driver gear turns a 45-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  39. 39.⚙️ A motor makes 240 turns a minute with a 20-tooth gear on it. That gear drives a 40-tooth gear. How many turns a minute does the 40-tooth gear make?
  40. 40.⚙️ A motor makes 150 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?

Answer key

  1. big (slow and strong)
  2. 60
  3. 48
  4. 3 times slower
  5. 80
  6. 60
  7. 100
  8. 40
  9. 8
  10. 20
  11. 3
  12. 20
  13. 9
  14. 4
  15. 6
  16. 12
  17. 45
  18. 16
  19. 5
  20. 8
  21. driver teeth
  22. 3
  23. 100
  24. 30
  25. 27
  26. 60
  27. 20
  28. 20
  29. 28
  30. 45
  31. 8
  32. 6
  33. 4
  34. 40
  35. 4
  36. 5
  37. 30
  38. 2
  39. 120
  40. 30

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