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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 92 · 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 90 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?
  2. 2.⚙️ A 20-tooth driver gear turns a 40-tooth driven gear. The driver turns 16 times. How many times does the driven gear turn?
  3. 3.⚙️ A 10-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  4. 4.⚙️ An 8-tooth driver gear turns a 24-tooth driven gear. The driven gear turns 3 times. How many times did the driver turn?
  5. 5.⚙️ A 10-tooth driver gear turns a 20-tooth driven gear. The driven gear turns 2 times. How many times did the driver turn?
  6. 6.⚙️ A 40-tooth driver gear turns an 8-tooth driven gear. The driver turns 1 time. How many times does the driven gear turn?
  7. 7.🔢 To climb a steep ramp, a robot needs a gear ratio that is … (a) never important (b) small (fast, weak) (c) zero (d) big (slow and strong)
  8. 8.🔢 Gear ratio = driven teeth ÷ … (a) wheel size (b) number of gears (c) driver teeth (d) motor volts
  9. 9.⚙️ A 15-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  10. 10.🔢 A gear ratio of 3 (driven ÷ driver) means the driven gear turns … (a) 3 times bigger (b) 3 times faster (c) 3 times slower (d) 3 times louder
  11. 11.⚙️ A motor makes 200 turns a minute with a 20-tooth gear on it. That gear drives a 100-tooth gear. How many turns a minute does the 100-tooth gear make?
  12. 12.⚙️ A motor makes 30 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?
  13. 13.⚙️ An 8-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  14. 14.⚙️ A 15-tooth driver gear turns a 30-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?
  15. 15.⚙️ An 8-tooth gear drives a 24-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  16. 16.⚙️ A motor makes 20 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.⚙️ A 20-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  18. 18.⚙️ A motor makes 550 turns a minute with a 12-tooth gear on it. That gear drives a 60-tooth gear. How many turns a minute does the 60-tooth gear make?
  19. 19.⚙️ A 20-tooth driver gear turns a 100-tooth driven gear. The driver turns 25 times. How many times does the driven gear turn?
  20. 20.⚙️ A 10-tooth driver gear turns a 20-tooth driven gear. The driven gear turns 1 time. How many times did the driver turn?
  21. 21.⚙️ A motor makes 120 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?
  22. 22.⚙️ A motor makes 160 turns a minute with a 10-tooth gear on it. That gear drives a 40-tooth gear. How many turns a minute does the 40-tooth gear make?
  23. 23.⚙️ A 15-tooth driver gear turns a 75-tooth driven gear. The driver turns 10 times. How many times does the driven gear turn?
  24. 24.⚙️ A 30-tooth driver gear turns a 10-tooth driven gear. The driver turns 2 times. How many times does the driven gear turn?
  25. 25.⚙️ A motor makes 200 turns a minute with a 15-tooth gear on it. That gear drives a 60-tooth gear. How many turns a minute does the 60-tooth gear make?
  26. 26.⚙️ A 48-tooth driver gear turns a 12-tooth driven gear. The driver turns 2 times. How many times does the driven gear turn?
  27. 27.⚙️ A 48-tooth driver gear turns a 12-tooth driven gear. The driver turns 10 times. How many times does the driven gear turn?
  28. 28.⚙️ A 45-tooth driver gear turns a 15-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  29. 29.⚙️ A 60-tooth driver gear turns a 15-tooth driven gear. The driver turns 8 times. How many times does the driven gear turn?
  30. 30.⚙️ A 10-tooth driver gear turns a 30-tooth driven gear. The driver turns 15 times. How many times does the driven gear turn?
  31. 31.⚙️ A motor makes 100 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?
  32. 32.⚙️ A 10-tooth gear drives a 20-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  33. 33.⚙️ A motor makes 240 turns a minute with a 10-tooth gear on it. That gear drives a 40-tooth gear. How many turns a minute does the 40-tooth gear make?
  34. 34.⚙️ A 15-tooth driver gear turns a 75-tooth driven gear. The driver turns 30 times. How many times does the driven gear turn?
  35. 35.⚙️ A 12-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  36. 36.⚙️ A 12-tooth driver gear turns a 24-tooth driven gear. The driven gear turns 4 times. How many times did the driver turn?
  37. 37.⚙️ An 8-tooth gear drives a 16-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  38. 38.⚙️ An 8-tooth driver gear turns a 40-tooth driven gear. The driven gear turns 2 times. How many times did the driver turn?
  39. 39.⚙️ A 12-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  40. 40.⚙️ An 8-tooth gear drives a 32-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?

Answer key

  1. 30
  2. 8
  3. 50
  4. 9
  5. 4
  6. 5
  7. big (slow and strong)
  8. driver teeth
  9. 45
  10. 3 times slower
  11. 40
  12. 10
  13. 16
  14. 2
  15. 3
  16. 10
  17. 60
  18. 110
  19. 5
  20. 2
  21. 40
  22. 40
  23. 2
  24. 6
  25. 50
  26. 8
  27. 40
  28. 9
  29. 32
  30. 5
  31. 50
  32. 2
  33. 60
  34. 6
  35. 48
  36. 8
  37. 2
  38. 10
  39. 36
  40. 4

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