1. MEASUREMENT OF
SPEED OF SOUND
IN AIR

2. OBJECTIVE To measure the speed of sound in air
using the resonance column.

3. THEORY c = fλ c = 4f(λ + 0.3d). c = VELOCITY OF SOUND IN AIR
d = DIAMETER OF THE RESONANCE TUBE = m
f = FREQUENCY
λ = WAVELENGTH

4. TOOLS
Resonance column
Tuning forks
Rubber hammer
water

5. RESONANCE TUBE
RUBBER HAMMER

6. TUNING FORKS

7. STEPS Fill water in the resonance column.
Select a tuning fork of known frequency.
Beat the tuning fork with a rubber hammer so that it vibrates.
Hold the tuning fork to the mouth of the resonance column.
Lower the water level by lowering the water reservoir on the
side of the tube.
6. Observe carefully for maximum resonance to occur.
7. Note the length where maximum resonance (maximum sound )
is produced .
8. This is the wavelength λ.

8. DATA c = 4f (λ + 0.3d) FREQUENCY (f) Hz WAVELENGTH( λ) m
SOU ND VELOCITY
(c ) m/s
256
288
320
c = 4f (λ + 0.3d)

9. CONCLUSION
Velocity of sound in air is = ______________ m/s.