Robotics Worksheet: Ultrasonic Distance Sensor
Robot tip (Half the echo path): Distance (cm) = 17 × echo time (ms), because 34 cm per ms ÷ 2 for there and back. Echo time (ms) = distance × 2 ÷ 34. Distance after driving = distance now − speed × time.
NameDateTime takenScore ___ / 40
- 1.📡 A robot is 230 cm from a wall and drives straight at it at 20 cm per second. How far from the wall is it after 2 seconds (in cm)?
- 2.📡 An object is 187 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
- 3.📡 What does an ultrasonic distance sensor send out? (a) radio music (b) water drops (c) sound too high to hear (d) bright light
- 4.📡 A distance sensor sends a sound pulse and hears the echo 16 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
- 5.📡 A robot is 160 cm from a wall and drives straight at it at 10 cm per second. How far from the wall is it after 8 seconds (in cm)?
- 6.📡 A robot stops if an object is closer than 60 cm. Its distance sensor hears the echo after 8 ms (sound: about 34 cm per ms). Does the robot stop? (a) Yes (b) No
- 7.📡 A robot stops if an object is closer than 100 cm. Its distance sensor hears the echo after 6 ms (sound: about 34 cm per ms). Does the robot stop? (a) No (b) Yes
- 8.📡 Which animal finds its way by echoes, like this sensor? (a) a snail (b) a cow (c) a bat (d) a goldfish
- 9.📡 A robot stops if an object is closer than 60 cm. Its distance sensor hears the echo after 1 ms (sound: about 34 cm per ms). Does the robot stop? (a) No (b) Yes
- 10.📡 Why do we halve the echo’s total path? (a) the sensor is half (b) sound is slow (c) to make it smaller (d) it goes there and back
- 11.📡 A robot stops if an object is closer than 60 cm. Its distance sensor hears the echo after 2 ms (sound: about 34 cm per ms). Does the robot stop? (a) Yes (b) No
- 12.📡 A robot is 250 cm from a wall and drives straight at it at 20 cm per second. How far from the wall is it after 9 seconds (in cm)?
- 13.📡 A robot stops if an object is closer than 60 cm. Its distance sensor hears the echo after 6 ms (sound: about 34 cm per ms). Does the robot stop? (a) Yes (b) No
- 14.📡 A robot is 250 cm from a wall and drives straight at it at 15 cm per second. How far from the wall is it after 3 seconds (in cm)?
- 15.📡 An object is 51 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
- 16.📡 A distance sensor sends a sound pulse and hears the echo 12 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
- 17.📡 An object is 255 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
- 18.📡 A robot stops if an object is closer than 50 cm. Its distance sensor hears the echo after 3 ms (sound: about 34 cm per ms). Does the robot stop? (a) No (b) Yes
- 19.📡 A robot is 190 cm from a wall and drives straight at it at 15 cm per second. How far from the wall is it after 8 seconds (in cm)?
- 20.📡 A robot is 240 cm from a wall and drives straight at it at 10 cm per second. How far from the wall is it after 4 seconds (in cm)?
- 21.📡 An object is 340 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
- 22.📡 A robot stops if an object is closer than 50 cm. Its distance sensor hears the echo after 4 ms (sound: about 34 cm per ms). Does the robot stop? (a) No (b) Yes
- 23.📡 An object is 272 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
- 24.📡 A robot is 100 cm from a wall and drives straight at it at 5 cm per second. How far from the wall is it after 2 seconds (in cm)?
- 25.📡 A robot stops if an object is closer than 30 cm. Its distance sensor hears the echo after 8 ms (sound: about 34 cm per ms). Does the robot stop? (a) No (b) Yes
- 26.📡 A distance sensor sends a sound pulse and hears the echo 3 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
- 27.📡 A robot stops if an object is closer than 100 cm. Its distance sensor hears the echo after 3 ms (sound: about 34 cm per ms). Does the robot stop? (a) Yes (b) No
- 28.📡 An object is 119 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
- 29.📡 A robot stops if an object is closer than 50 cm. Its distance sensor hears the echo after 7 ms (sound: about 34 cm per ms). Does the robot stop? (a) Yes (b) No
- 30.📡 A robot is 260 cm from a wall and drives straight at it at 15 cm per second. How far from the wall is it after 16 seconds (in cm)?
- 31.📡 A robot stops if an object is closer than 60 cm. Its distance sensor hears the echo after 3 ms (sound: about 34 cm per ms). Does the robot stop? (a) No (b) Yes
- 32.📡 A distance sensor sends a sound pulse and hears the echo 20 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
- 33.📡 A robot is 100 cm from a wall and drives straight at it at 15 cm per second. How far from the wall is it after 5 seconds (in cm)?
- 34.📡 A distance sensor sends a sound pulse and hears the echo 19 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
- 35.📡 A robot is 260 cm from a wall and drives straight at it at 10 cm per second. How far from the wall is it after 23 seconds (in cm)?
- 36.📡 A robot is 230 cm from a wall and drives straight at it at 15 cm per second. How far from the wall is it after 3 seconds (in cm)?
- 37.📡 An object is 17 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
- 38.📡 An object is 34 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
- 39.📡 An object is 323 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
- 40.📡 A distance sensor sends a sound pulse and hears the echo 14 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
Answer key
- 190
- 11
- sound too high to hear
- 272
- 80
- No
- No
- a bat
- Yes
- it goes there and back
- Yes
- 70
- No
- 205
- 3
- 204
- 15
- No
- 70
- 200
- 20
- No
- 16
- 90
- No
- 51
- Yes
- 7
- No
- 20
- Yes
- 340
- 25
- 323
- 30
- 185
- 1
- 2
- 19
- 238
Free robotics lessons, practice and worksheets at talentjr.in/robotics-for-kids