The greater the temperature, the greater the volume - this is Charles's law, said by Jacques Charles, a French inventor, scientist, and mathematician.
Speed = (frequency)x(wavelength).
Frequency = 6 Hz
Wavelength = 9mm = 0.009m.
Speed = (6 Hz) x (0.009m) = 0.054 m/s or 54 mm/sec.
Explanation:
Work Done = Force * Displacement
= (4N)(10m) = 40J.
Power = Work Done / Time
= (40J)/(20s) = 2J/s = 2 Nm/sec.
I just need points to ask my own question.