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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 155 · 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 150 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?
  2. 2.🔢 Gear ratio = driven teeth ÷ … (a) number of gears (b) driver teeth (c) wheel size (d) motor volts
  3. 3.⚙️ A 20-tooth driver gear turns a 40-tooth driven gear. The driven gear turns 8 times. How many times did the driver turn?
  4. 4.⚙️ A 20-tooth driver gear turns a 60-tooth driven gear. The driver turns 9 times. How many times does the driven gear turn?
  5. 5.⚙️ An 8-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  6. 6.⚙️ A 10-tooth driver gear turns a 50-tooth driven gear. The driven gear turns 5 times. How many times did the driver turn?
  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 turns a 30-tooth driven gear. The driven gear turns 1 time. How many times did the driver turn?
  9. 9.⚙️ A motor makes 360 turns a minute with a 12-tooth gear on it. That gear drives a 48-tooth gear. How many turns a minute does the 48-tooth gear make?
  10. 10.⚙️ A motor makes 200 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?
  11. 11.⚙️ A 10-tooth gear drives a 40-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  12. 12.⚙️ A motor makes 120 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.🔢 To climb a steep ramp, a robot needs a gear ratio that is … (a) small (fast, weak) (b) big (slow and strong) (c) never important (d) zero
  14. 14.🔢 A gear ratio of 3 (driven ÷ driver) means the driven gear turns … (a) 3 times bigger (b) 3 times louder (c) 3 times slower (d) 3 times faster
  15. 15.⚙️ A 12-tooth driver gear turns a 24-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?
  16. 16.⚙️ A 12-tooth driver gear turns a 24-tooth driven gear. The driver turns 20 times. How many times does the driven gear turn?
  17. 17.⚙️ A motor makes 210 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?
  18. 18.⚙️ A 15-tooth driver gear turns a 45-tooth driven gear. The driven gear turns 1 time. How many times did the driver turn?
  19. 19.⚙️ A 30-tooth driver gear turns a 10-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?
  20. 20.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driver turns 16 times. How many times does the driven gear turn?
  21. 21.⚙️ A 60-tooth driver gear turns a 12-tooth driven gear. The driver turns 1 time. How many times does the driven gear turn?
  22. 22.⚙️ A 15-tooth driver gear turns a 45-tooth driven gear. The driven gear turns 4 times. How many times did the driver turn?
  23. 23.⚙️ An 8-tooth gear drives a 32-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  24. 24.⚙️ A motor makes 360 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?
  25. 25.⚙️ A 16-tooth driver gear turns an 8-tooth driven gear. The driver turns 5 times. How many times does the driven gear turn?
  26. 26.⚙️ 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?
  27. 27.⚙️ A motor makes 400 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?
  28. 28.⚙️ A motor makes 480 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?
  29. 29.⚙️ A motor makes 150 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?
  30. 30.⚙️ A motor makes 440 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?
  31. 31.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driver turns 8 times. How many times does the driven gear turn?
  32. 32.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driver turns 32 times. How many times does the driven gear turn?
  33. 33.⚙️ A 12-tooth driver gear turns a 60-tooth driven gear. The driver turns 5 times. How many times does the driven gear turn?
  34. 34.⚙️ A 20-tooth driver gear turns an 80-tooth driven gear. The driven gear turns 1 time. How many times did the driver turn?
  35. 35.⚙️ A 15-tooth gear drives a 45-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  36. 36.⚙️ An 8-tooth gear drives a 40-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  37. 37.⚙️ A 10-tooth driver gear turns a 50-tooth driven gear. The driven gear turns 8 times. How many times did the driver turn?
  38. 38.⚙️ A 15-tooth gear drives a 60-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  39. 39.⚙️ A 24-tooth driver gear turns a 12-tooth driven gear. The driver turns 10 times. How many times does the driven gear turn?
  40. 40.⚙️ A 15-tooth driver gear turns a 60-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?

Answer key

  1. 30
  2. driver teeth
  3. 16
  4. 3
  5. 32
  6. 25
  7. 100
  8. 3
  9. 90
  10. 100
  11. 4
  12. 40
  13. big (slow and strong)
  14. 3 times slower
  15. 2
  16. 10
  17. 70
  18. 3
  19. 12
  20. 4
  21. 5
  22. 12
  23. 4
  24. 90
  25. 10
  26. 20
  27. 80
  28. 120
  29. 30
  30. 110
  31. 2
  32. 8
  33. 1
  34. 4
  35. 3
  36. 5
  37. 40
  38. 4
  39. 20
  40. 1

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