Design Information Transfer

Grade 4 Science Worksheet - Building Confidence

Circle the answer.

1. 1.

   Code: blue flag = rain coming, yellow flag = sunny day. A sailor sees a blue flag. What should she expect?

   • rain
   • a sunny day
   • strong wind only
2. 2.

   Two flash patterns look almost the same. What problem could this cause?

   • the receiver could mix up the messages
   • the flashlight could break
   • the messages would travel too far
3. 3.

   Which signal uses sound to send a message?

   • a fire alarm beeping
   • a traffic light changing
   • a flag waving
4. 4.

   Why do traffic lights use both color and position (red on top)?

   • putting red on top makes the lights cost less
   • a driver who cannot tell colors apart can still read the signal
   • the top light is always brighter than the others
5. 5.

   Two scouts use mirrors to flash sunlight as signals. When will this design not work?

   • on a sunny day
   • when they are far apart in the open
   • on a cloudy day