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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 187 · 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.🔢 Gear ratio = driven teeth ÷ … (a) wheel size (b) driver teeth (c) number of gears (d) motor volts
  2. 2.⚙️ An 8-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) small (fast, weak) (c) big (slow and strong) (d) zero
  4. 4.⚙️ A 20-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  5. 5.⚙️ A 15-tooth gear drives a 60-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  6. 6.⚙️ A 15-tooth gear drives a 75-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  7. 7.⚙️ An 8-tooth driver gear turns a 40-tooth driven gear. The driven gear turns 6 times. How many times did the driver turn?
  8. 8.⚙️ A motor makes 100 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?
  9. 9.⚙️ A 12-tooth driver gear turns a 48-tooth driven gear. The driver turns 12 times. How many times does the driven gear turn?
  10. 10.⚙️ A 12-tooth driver gear turns a 48-tooth driven gear. The driver turns 36 times. How many times does the driven gear turn?
  11. 11.⚙️ A motor makes 360 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?
  12. 12.⚙️ A motor makes 360 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 gear drives a 24-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  14. 14.⚙️ A 10-tooth driver gear turns a 40-tooth driven gear. The driver turns 40 times. How many times does the driven gear turn?
  15. 15.⚙️ A 15-tooth gear drives a 30-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  16. 16.⚙️ A 15-tooth driver gear turns a 60-tooth driven gear. The driven gear turns 4 times. How many times did the driver turn?
  17. 17.⚙️ A 10-tooth driver gear turns a 20-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?
  18. 18.⚙️ A 75-tooth driver gear turns a 15-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?
  19. 19.⚙️ A 20-tooth gear drives an 80-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  20. 20.⚙️ A motor makes 440 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?
  21. 21.⚙️ A 20-tooth driver gear turns a 40-tooth driven gear. The driven gear turns 7 times. How many times did the driver turn?
  22. 22.⚙️ A 30-tooth driver gear turns a 10-tooth driven gear. The driver turns 9 times. How many times does the driven gear turn?
  23. 23.⚙️ A 10-tooth gear drives a 50-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  24. 24.⚙️ A 10-tooth driver gear turns a 20-tooth driven gear. The driven gear turns 4 times. How many times did the driver turn?
  25. 25.⚙️ A motor makes 300 turns a minute with a 10-tooth gear on it. That gear drives a 50-tooth gear. How many turns a minute does the 50-tooth gear make?
  26. 26.⚙️ A 32-tooth driver gear turns an 8-tooth driven gear. The driver turns 7 times. How many times does the driven gear turn?
  27. 27.⚙️ A 10-tooth driver gear turns a 20-tooth driven gear. The driver turns 18 times. How many times does the driven gear turn?
  28. 28.⚙️ A motor makes 120 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?
  29. 29.⚙️ A 12-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  30. 30.⚙️ An 80-tooth driver gear turns a 20-tooth driven gear. The driver turns 8 times. How many times does the driven gear turn?
  31. 31.⚙️ A motor makes 400 turns a minute with a 10-tooth gear on it. That gear drives a 50-tooth gear. How many turns a minute does the 50-tooth gear make?
  32. 32.🔢 A gear ratio of 3 (driven ÷ driver) means the driven gear turns … (a) 3 times faster (b) 3 times slower (c) 3 times louder (d) 3 times bigger
  33. 33.⚙️ An 8-tooth driver gear turns a 40-tooth driven gear. The driver turns 10 times. How many times does the driven gear turn?
  34. 34.⚙️ A 10-tooth driver gear turns a 50-tooth driven gear. The driver turns 50 times. How many times does the driven gear turn?
  35. 35.⚙️ A 20-tooth driver gear turns a 60-tooth driven gear. The driven gear turns 1 time. How many times did the driver turn?
  36. 36.⚙️ A 15-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  37. 37.⚙️ A motor makes 40 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?
  38. 38.⚙️ A 75-tooth driver gear turns a 15-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  39. 39.⚙️ A motor makes 350 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?
  40. 40.⚙️ A motor makes 60 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?

Answer key

  1. driver teeth
  2. 24
  3. big (slow and strong)
  4. 100
  5. 4
  6. 5
  7. 30
  8. 20
  9. 3
  10. 9
  11. 120
  12. 120
  13. 3
  14. 10
  15. 2
  16. 16
  17. 2
  18. 20
  19. 4
  20. 110
  21. 14
  22. 27
  23. 5
  24. 8
  25. 60
  26. 28
  27. 9
  28. 40
  29. 36
  30. 32
  31. 80
  32. 3 times slower
  33. 2
  34. 10
  35. 3
  36. 30
  37. 20
  38. 15
  39. 70
  40. 30

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