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.📡 Which object is hardest for an echo sensor to notice? (a) a wooden box (b) a flat wall (c) a metal door (d) a soft foam cushion
- 2.📡 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?
- 3.📡 Why do we halve the echo’s total path? (a) to make it smaller (b) the sensor is half (c) it goes there and back (d) sound is slow
- 4.📡 What does an ultrasonic distance sensor send out? (a) water drops (b) sound too high to hear (c) radio music (d) bright light
- 5.📡 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)?
- 6.📡 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
- 7.📡 A robot is 280 cm from a wall and drives straight at it at 20 cm per second. How far from the wall is it after 4 seconds (in cm)?
- 8.📡 A robot stops if an object is closer than 100 cm. Its distance sensor hears the echo after 7 ms (sound: about 34 cm per ms). Does the robot stop? (a) Yes (b) No
- 9.📡 A robot is 220 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)?
- 10.📡 A distance sensor sends a sound pulse and hears the echo 4 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
- 11.📡 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?
- 12.📡 An object is 153 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
- 13.📡 In these lessons, sound travels about how far in 1 millisecond? (a) 3 cm (b) 34 cm (c) 340 cm (d) 1 km
- 14.📡 A distance sensor sends a sound pulse and hears the echo 9 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
- 15.📡 A distance sensor sends a sound pulse and hears the echo 15 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
- 16.📡 A robot stops if an object is closer than 60 cm. Its distance sensor hears the echo after 4 ms (sound: about 34 cm per ms). Does the robot stop? (a) Yes (b) No
- 17.📡 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?
- 18.📡 Which animal finds its way by echoes, like this sensor? (a) a cow (b) a snail (c) a goldfish (d) a bat
- 19.📡 A robot is 160 cm from a wall and drives straight at it at 5 cm per second. How far from the wall is it after 8 seconds (in cm)?
- 20.📡 An object is 68 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
- 21.📡 A distance sensor sends a sound pulse and hears the echo 6 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
- 22.📡 An object is 170 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
- 23.📡 An object is 136 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
- 24.📡 A distance sensor sends a sound pulse and hears the echo 8 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
- 25.📡 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)?
- 26.📡 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) Yes (b) No
- 27.📡 An object is 102 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
- 28.📡 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)?
- 29.📡 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
- 30.📡 A robot stops if an object is closer than 100 cm. Its distance sensor hears the echo after 2 ms (sound: about 34 cm per ms). Does the robot stop? (a) Yes (b) No
- 31.📡 An object is 85 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
- 32.📡 A distance sensor sends a sound pulse and hears the echo 7 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
- 33.📡 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) Yes (b) No
- 34.📡 A distance sensor sends a sound pulse and hears the echo 18 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
- 35.📡 A robot is 280 cm from a wall and drives straight at it at 5 cm per second. How far from the wall is it after 9 seconds (in cm)?
- 36.📡 A robot is 170 cm from a wall and drives straight at it at 10 cm per second. How far from the wall is it after 7 seconds (in cm)?
- 37.📡 A robot stops if an object is closer than 50 cm. Its distance sensor hears the echo after 1 ms (sound: about 34 cm per ms). Does the robot stop? (a) No (b) Yes
- 38.📡 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)?
- 39.📡 A distance sensor sends a sound pulse and hears the echo 5 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
- 40.📡 A robot stops if an object is closer than 100 cm. Its distance sensor hears the echo after 1 ms (sound: about 34 cm per ms). Does the robot stop? (a) Yes (b) No
Answer key
- a soft foam cushion
- 20
- it goes there and back
- sound too high to hear
- 51
- Yes
- 200
- No
- 180
- 68
- 16
- 9
- 34 cm
- 153
- 255
- No
- 19
- a bat
- 120
- 4
- 102
- 10
- 8
- 136
- 323
- Yes
- 6
- 238
- No
- Yes
- 5
- 119
- No
- 306
- 235
- 100
- Yes
- 204
- 85
- Yes
Free robotics lessons, practice and worksheets at talentjr.in/robotics-for-kids