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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 172 · 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 280 turns a minute with an 8-tooth gear on it. That gear drives a 32-tooth gear. How many turns a minute does the 32-tooth gear make?
  2. 2.⚙️ A motor makes 100 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.🔢 To climb a steep ramp, a robot needs a gear ratio that is … (a) never important (b) zero (c) small (fast, weak) (d) big (slow and strong)
  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 30-tooth driver gear turns a 10-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  6. 6.⚙️ A 15-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  7. 7.🔢 Gear ratio = driven teeth ÷ … (a) motor volts (b) wheel size (c) number of gears (d) driver teeth
  8. 8.⚙️ A motor makes 180 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?
  9. 9.⚙️ A 15-tooth driver gear turns a 60-tooth driven gear. The driver turns 36 times. How many times does the driven gear turn?
  10. 10.⚙️ A 10-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  11. 11.⚙️ 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?
  12. 12.⚙️ A motor makes 160 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?
  13. 13.⚙️ An 8-tooth driver gear turns a 24-tooth driven gear. The driver turns 21 times. How many times does the driven gear turn?
  14. 14.🔢 A gear ratio of 3 (driven ÷ driver) means the driven gear turns … (a) 3 times bigger (b) 3 times slower (c) 3 times faster (d) 3 times louder
  15. 15.⚙️ A 20-tooth gear drives a 60-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  16. 16.⚙️ An 8-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  17. 17.⚙️ A 20-tooth gear drives a 100-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  18. 18.⚙️ A 20-tooth driver gear turns a 40-tooth driven gear. The driver turns 2 times. How many times does the driven gear turn?
  19. 19.⚙️ An 8-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  20. 20.⚙️ A 12-tooth driver gear turns a 36-tooth driven gear. The driven gear turns 2 times. How many times did the driver turn?
  21. 21.⚙️ A 10-tooth gear drives a 20-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  22. 22.⚙️ An 8-tooth driver gear turns a 16-tooth driven gear. The driven gear turns 7 times. How many times did the driver turn?
  23. 23.⚙️ A 15-tooth driver gear turns a 30-tooth driven gear. The driver turns 14 times. How many times does the driven gear turn?
  24. 24.⚙️ A 24-tooth driver gear turns an 8-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  25. 25.⚙️ A 15-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  26. 26.⚙️ A motor makes 160 turns a minute with an 8-tooth gear on it. That gear drives a 32-tooth gear. How many turns a minute does the 32-tooth gear make?
  27. 27.⚙️ A 20-tooth gear drives an 80-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  28. 28.⚙️ A 40-tooth driver gear turns an 8-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  29. 29.⚙️ A 24-tooth driver gear turns a 12-tooth driven gear. The driver turns 2 times. How many times does the driven gear turn?
  30. 30.⚙️ A 12-tooth driver gear turns a 36-tooth driven gear. The driven gear turns 1 time. How many times did the driver turn?
  31. 31.⚙️ A 15-tooth driver gear turns a 60-tooth driven gear. The driven gear turns 5 times. How many times did the driver turn?
  32. 32.⚙️ A 12-tooth driver gear turns a 48-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?
  33. 33.⚙️ A 15-tooth driver gear turns a 75-tooth driven gear. The driver turns 40 times. How many times does the driven gear turn?
  34. 34.⚙️ A 45-tooth driver gear turns a 15-tooth driven gear. The driver turns 2 times. How many times does the driven gear turn?
  35. 35.⚙️ A 10-tooth driver gear turns a 20-tooth driven gear. The driver turns 18 times. How many times does the driven gear turn?
  36. 36.⚙️ A 60-tooth driver gear turns a 20-tooth driven gear. The driver turns 2 times. How many times does the driven gear turn?
  37. 37.⚙️ A motor makes 400 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?
  38. 38.⚙️ A 15-tooth driver gear turns a 60-tooth driven gear. The driven gear turns 6 times. How many times did the driver turn?
  39. 39.⚙️ A 20-tooth driver gear turns a 100-tooth driven gear. The driven gear turns 4 times. How many times did the driver turn?
  40. 40.⚙️ A 15-tooth driver gear turns a 30-tooth driven gear. The driver turns 12 times. How many times does the driven gear turn?

Answer key

  1. 70
  2. 50
  3. big (slow and strong)
  4. 100
  5. 9
  6. 30
  7. driver teeth
  8. 90
  9. 9
  10. 30
  11. 20
  12. 40
  13. 7
  14. 3 times slower
  15. 3
  16. 24
  17. 5
  18. 1
  19. 32
  20. 6
  21. 2
  22. 14
  23. 7
  24. 9
  25. 60
  26. 40
  27. 4
  28. 30
  29. 4
  30. 3
  31. 20
  32. 1
  33. 8
  34. 6
  35. 9
  36. 6
  37. 80
  38. 24
  39. 20
  40. 6

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