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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 218 · 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 20-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  2. 2.⚙️ A motor makes 180 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?
  3. 3.⚙️ A 24-tooth driver gear turns a 12-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  4. 4.🔢 Gear ratio = driven teeth ÷ … (a) wheel size (b) motor volts (c) number of gears (d) driver teeth
  5. 5.⚙️ A motor makes 400 turns a minute with a 20-tooth gear on it. That gear drives an 80-tooth gear. How many turns a minute does the 80-tooth gear make?
  6. 6.⚙️ A 20-tooth driver gear turns a 10-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  7. 7.⚙️ A 20-tooth driver gear turns an 80-tooth driven gear. The driver turns 20 times. How many times does the driven gear turn?
  8. 8.⚙️ A 15-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  9. 9.🔢 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
  10. 10.⚙️ An 8-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  11. 11.⚙️ A 15-tooth driver gear turns a 45-tooth driven gear. The driver turns 18 times. How many times does the driven gear turn?
  12. 12.⚙️ A 15-tooth driver gear turns a 45-tooth driven gear. The driven gear turns 4 times. How many times did the driver turn?
  13. 13.⚙️ A motor makes 400 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?
  14. 14.⚙️ A 36-tooth driver gear turns a 12-tooth driven gear. The driver turns 10 times. How many times does the driven gear turn?
  15. 15.⚙️ A 30-tooth driver gear turns a 10-tooth driven gear. The driver turns 2 times. How many times does the driven gear turn?
  16. 16.⚙️ A 10-tooth gear drives a 30-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  17. 17.🔢 To climb a steep ramp, a robot needs a gear ratio that is … (a) big (slow and strong) (b) never important (c) small (fast, weak) (d) zero
  18. 18.⚙️ A motor makes 550 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?
  19. 19.⚙️ A 100-tooth driver gear turns a 20-tooth driven gear. The driver turns 10 times. How many times does the driven gear turn?
  20. 20.⚙️ A 48-tooth driver gear turns a 12-tooth driven gear. The driver turns 7 times. How many times does the driven gear turn?
  21. 21.⚙️ A motor makes 50 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?
  22. 22.⚙️ A 12-tooth driver gear turns a 24-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  23. 23.⚙️ A 20-tooth driver gear turns an 80-tooth driven gear. The driven gear turns 5 times. How many times did the driver turn?
  24. 24.⚙️ A motor makes 60 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?
  25. 25.⚙️ An 8-tooth gear drives a 24-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  26. 26.⚙️ A 12-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  27. 27.⚙️ A motor makes 350 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?
  28. 28.⚙️ A 15-tooth driver gear turns a 75-tooth driven gear. The driver turns 35 times. How many times does the driven gear turn?
  29. 29.⚙️ A 10-tooth driver gear turns a 40-tooth driven gear. The driver turns 8 times. How many times does the driven gear turn?
  30. 30.⚙️ A 20-tooth driver gear turns a 100-tooth driven gear. The driver turns 40 times. How many times does the driven gear turn?
  31. 31.⚙️ A 10-tooth gear drives a 50-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  32. 32.⚙️ A 45-tooth driver gear turns a 15-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  33. 33.⚙️ A 15-tooth driver gear turns a 30-tooth driven gear. The driver turns 14 times. How many times does the driven gear turn?
  34. 34.⚙️ A 15-tooth driver gear turns a 75-tooth driven gear. The driver turns 10 times. How many times does the driven gear turn?
  35. 35.⚙️ A 10-tooth gear drives a 20-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  36. 36.⚙️ A 60-tooth driver gear turns a 20-tooth driven gear. The driver turns 7 times. How many times does the driven gear turn?
  37. 37.⚙️ A motor makes 40 turns a minute with a 20-tooth gear on it. That gear drives an 80-tooth gear. How many turns a minute does the 80-tooth gear make?
  38. 38.⚙️ A 20-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  39. 39.⚙️ A 12-tooth gear drives a 24-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  40. 40.⚙️ A 10-tooth driver gear turns a 30-tooth driven gear. The driver turns 27 times. How many times does the driven gear turn?

Answer key

  1. 40
  2. 90
  3. 12
  4. driver teeth
  5. 100
  6. 12
  7. 5
  8. 75
  9. 3 times slower
  10. 24
  11. 6
  12. 12
  13. 80
  14. 30
  15. 6
  16. 3
  17. big (slow and strong)
  18. 110
  19. 50
  20. 28
  21. 10
  22. 3
  23. 20
  24. 30
  25. 3
  26. 48
  27. 70
  28. 7
  29. 2
  30. 8
  31. 5
  32. 9
  33. 7
  34. 2
  35. 2
  36. 21
  37. 10
  38. 80
  39. 2
  40. 9

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