1. Determining wave frequency
from a graph

2. f
• Frequency = #of cycles/time
• Measured in Hertz (Hz)

3. • 1 cycle = 1 full wave to
repeat itself

4. 31 2 4 5 6 7 8 9 10 11 12
Time in seconds
3 cycles

5. from 0 to 12 seconds
31 2 4 5 6 7 8 9 10 11 12
Time in seconds
0

6. f=3 /12 s = ¼ Hz
31 2 4 5 6 7 8 9 10 11 12
Time in seconds

7. • Or determine the time for 1 full wave cycle

8. 1 cycle in 4 seconds= ¼ Hz
31 2 5 6 7 8 9 10 11 12
Time in seconds
0 4

9. • Period symbol T
• The time for 1 cycle

10. The period for 1 wave is 4
seconds T=4
31 2 4 5 6 7 8 9 10 11 12
Time in seconds

11. What is the frequency?
0 2 4 6 8 10 12 14 16 18 20
Time in seconds
22 24

12. ?
0 2 4 6 8 10 12 14 16 18 20
Time in seconds
22 24
3 cycles 0 to 24 seconds

13. 0 2 4 6 8 10 12 14 16 18 20
Time in seconds
22 24
3 cycles 0 to 24 seconds3/24 s= 1/8 Hz

14. OR
• Frequency – 1 cycle in x seconds

15. f=1 cycle in 8 seconds= 1/8 Hz
0 2 4 6 8 10 12 14 16 18 20
Time in seconds
22 24

17. • On a piece of paper
number 1 through 3 and
determine the frequency
of the following waves.

18. #1 f= ?
0 1 2 3 4 5 6 7 8 9 10 11 12
Time seconds

19. #2 f= ?
Time seconds
0 2 4 6 8 10 12 14 16 18 20 22 22 24 26

20. #3 f = ?
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70
Time seconds

21. • Check your answers

22. #1 f= 1/8 Hz
0 1 2 3 4 5 6 7 9 10 11 12
Time seconds
8

23. #2 f= 1/8 Hz
Time seconds
0 2 4 6 10 12 14 16 18 20 22 22 24 268

24. #3 f = 1/20 Hz
0 5 10 15 25 30 35 40 45 50 55 60 65 70
Time seconds
20