The document is a presentation on simple harmonic motion, bow and shock waves, and sound waves. It includes: 1) A definition and derivation of the equation of simple harmonic motion, where the restoring force is directly proportional to displacement. 2) An explanation of bow waves in water and shock waves in air caused by moving objects, how they propagate, and their effects. 3) Properties of sound waves including that they are longitudinal waves that propagate through a medium, with loudness determined by amplitude and pitch by frequency.

2. Presented to :
Sir Sikandar Khan

3. Presented By :
 Malik Armughan
 Hamza Ali
 Hamza Abbas
 BEE-012
 BEE-064
 BEE-074

4. Topics :
 Simple Harmonic Motion
 Bow & Shock Waves
 Sound

5. Simple Harmonic MotionBy Malik Armughan Bhutta

6. What is SHM ?
In mechanics and physics, simple
harmonic motion is a type of periodic
motion where the restoring force is
directly proportional to the
displacement

7. Derivation of Equation :
Let us consider a mass m attached to one
end of an elastic spring which can move
freely on a frictionless horizontal surface as
fig 1
When displaced towards right through a
distance x . Fig 2
The force at that instant is given by Hooke’s
law
F= kX
Where k is a constant known as Spring
constant
Due elasticity , spring opposes tha applied
force that force is called Restoring force
which is equal and opposite to applied force
F = -kx

8. F = -kx
The negative sign indicates that F is
directed opposite to X . Towards the
equilibrium position . Thus the restoring
force is directly proportional to displacement
x always towards equilibrium .
When mass is released , it begins to oscillate
about the equilibrium position
The oscillatory motion taking place under the
action of such a restoring force is known as
Simple Harmonic Motion (SHM)

9. F = ma
by comparing
-kx = ma
a =-(k/m)x
a α -x
The acceleration a produce in the mass m due to restoring force can be calculated using
Second law of motion

10. “
”
The acceleration at any instant of a
body executing SHM is proportional
to displacement and is always
directed towards its mean position
a α -x

11. Bow and Shock Waves

12. Bow Waves
A BOW waves is the wave at
the bow of a ship when it
moves through the water
The size of the bow wave is a function of the speed of
the ship, water depth, and the shape of the bow.
The bow wave carries energy away from the ship at
the expense of its kinetic energy—it slows the ship

13. As the bow wave
spreads out, it defines
the outer limits of a
ship's wake. A large bow
wave slows the ship
down, is a risk to
smaller boats, and in a
harbor can damage
shore facilities and
moored ships.
Therefore, ship hulls are
generally designed to
produce as small a bow
wave as possible.

14. Shock Waves :
The waves which caused
disturbance in air by any object
in the shape of V is called shock
waves .
 The difference is bow waves produce in water and the shock waves in air

15. The figure shows
the disturbance
caused by an object
(aero plane) in air .
They propagate in
the shape of V in
the medium .

16. Sound Waves

17. Sound waves , infect are those waves which
produce hearing effect in our ears.
In Physics, sound is a Vibration that propagates as a typically
audible Mechanical wave of Pressure and displacement,
through a medium such as air, and water.
 These waves are originally the Longitudinal and
Transvers waves
 We generally take sound waves as longitudinal
waves made by partial vibration

18. Propagation of Sound :
Sound recovered a medium for propagation
 Solid : fast speed
 Liquid : Medium speed
 Gas : slow speed
 Vacuum : no travel
A Medium is a medium is a metiral that helps the sound
(energy ) to transfer

19. Properties of sound :
Sound has the same properties as any wave have
 Loudness
 Pitch
 Interference
 Reflection

20. What is the Loudness of
a Sound Wave?
The loudness of a sound depends
on the amplitude of the wave.
The bigger the amplitude, the
louder the sound.

21. What is the Pitch of a Sound
Wave?
The pitch of a sound (how high the note is)
depends on the frequency of the wave.
The higher the frequency, the higher the pitch.
Sound is a longitudinal wave and so it is
difficult to show the amplitude and frequency on a diagram.
A microphone can change the sound wave into
an alternating current that can be displayed
as a transverse wave on a CRO. This makes it
easier to show the affect of amplitude and frequency
on loudness and pitch

22. Speed of Sound
Speed of sound can be calculated by the given formula
c= √k∕ρ
Where , C is the speed of sound
K is the co-efficient of stiffness (bulk modulus )
ρ is the Density
The speed of sound is approx. 343m∕s (1,230 km/h; 767 mph )

23. Reflection:
Reflection is the change in direction of a
wavefront at an interface between two
different media

24. Interference:
In physics, interference is a
phenomenon in which two waves
superpose to form a resultant
wave of greater or lower amplitude.

25. References :
 Fundamentals of Physics
(by Jearl Walker clevelan state
University)
 Wikipedia
 Text Book of Physics (PTBBL)
 Google Search Engine