Lightning

Lightning

Pencil and paperOnline interactive
Overview
Using this Resource
Connecting to the Curriculum
Marking Student Responses
Working with Students
Further Resources
This task is about the relationship between thunder and lightning.
thunderbolt-md.png
You can work out roughly how far away a thunderstorm is by counting the number of seconds between when you see the flash of lightning, and when you hear the sound of thunder.
Then you divide the number of seconds by three to get the distance in kilometres.   

Question

a)  i)  Why do you see lightning before hearing the thunder?   

    • Light travels much faster than sound. 

    • Your senses will always detect light quicker.

    • The sound waves are often muffled by the clouds.

    • The lightning flash is very bright.  

Explain your answer.

Question 3Change answer

     ii)  The time between the lightning and the thunder was 12 seconds.
           How far away was the thunderstorm when this occurred?  kilometres

Question

b)  Tall buildings are often struck by lightning but they are protected by a rod called a lightning conductor.
     This rod leads to the ground, so that when lightning strikes the electricity can pass through it, without causing any harm.
     Lightning rods are most likely made out of:

    • concrete.

    • rubber.

    • metal.

    • wood.

Explain your answer.
Task administration: 
This task can be completed with pencil and paper or online (with auto marking displayed to students).
Level:
4
Curriculum info: 
Science, Knowledge, Planet Earth
Keywords: 
interacting systems, lightning
Description of task: 
Students answer two multiple-choice questions about lightning and determine how far away a thunderstorm is by doing a calculation.
Making Better Sense: 
Features
Answers/responses: 
 

Y8 (05/1998)
a) i)
ii)		 A*  Light travels much faster than sound.
4		 easy
easy
b)    C  metal easy

*NOTE:  Sound travels at 331.4 ms/s in air, hence it takes three seconds to go 1 km.

Diagnostic and formative information: 
  Common error
b) Option B (Your senses will always detect light quicker.) chosen by 20% of the students.