Vibration and Waves questions

Penerbit Erlangga. 

Science text book B for Grade 8

1. What would be the motion of 1 3/4 vibration of a pendulum will be?

Answer: 1-2-3-2-1-2-3-2

2. A spring mass system moves a-b-c-b-a (b being its center point) its motion is?

Answer: 1 Vibration

3. The number of vibrations performed every second is called?

Answer: The Frequency

4. If 240 Vibrations happens in 2 minutes, its period is?

Answer: 1/2 Seconds

5. A period of a swing is 10 seconds. In every minute, the pendulum performs how many swings?

Answer: 6 Swings

6. If in 1/2 seconds a ruler moves in the pattern a-b-c-b-c, the period of the vibration made by the ruler is?

Answer: 1/2 Seconds

7. If the frequency of a vibration is 300Hz, the period is?

Answer: 

P: 1/F

P:1/300

8. A pendulum performs swings with a frequency of 25Hz. The number of Vibrations it can make within a minute is?

Answer: 25x60: 1500 

9. Planet Mercury revolves the sun with a frequency of 8x10^-6Hz. The period of planet mercury revolving the sun is?

Answer:

P: 1/F

P:1/8x10^-6 Seconds

10. The number of waves performed in every second is called?

Answer: The Frequency

11. If 30,000 waves are performed in 30 seconds then its frequency is?

Answer: 

F: n/t

F:30000/30

F: 1000Hz

12.The time it takes for 2.5 vibrations for a wave is 0.5 seconds, the frequency is?

Answer:

0.5 seconds: 2 vibrations

1 second: 4 vibration

13. If a frequency of a wave is 600Hz and the velocity is 300 m/s, the wavelength is?

Answer:

V: Wl x F

Wl: V/F

Wl: 300/600

Wl: 0.5m

14. 2 vibrations of a wave has a wavelength of 4m and the distance from the furthest point to the other furthest point is 6m. Find the amplitude, wavelength, and frequency if the velocity of the wave is 200 m/s.

Answer:

Amplitude: 6/2: 3m

Wavelength: 4/2: 2m

V: Wl x F

200: 2x F

F: 200/2

F: 100Hz

15. If the vibration direction is perpendicular to the direction of the wave propagation, it means the wave is what wave?

Answer: Transverse Wave 

16.The velocity of a wave is 300m/s and its frequency is 450Hz. The wavelength is?

Answer:

V: Wl x F

Wl: V/F

Wl: 300/450

Wl: 2/3m

17. Sound propagates in the air with a speed of 400 m/s. If the frequency of the keynote a is 500 Hz, then the wavelength is?

Answer: 

V: Wl x F

Wl: V/F

Wl: 400/500

Wl: 0.8m