SPM Physics

1. Waves transfer energy without transfering the matter.
2. Transverse wave's particles vibrate perpendicular to the wave direction.
3. Longitudinal wave's particles vibrate parallel to the wave direction.
4. The amplitude of a wave determines its energy. Higher amplitude has greater energy.
5. Damping of wave causes decrease in amplitude & energy.
6. Waves' wavefront is always pependicular to the direction of the waves.
7. Waves undergo all of these phenomena; reflection, refraction, diffraction & interference.
8. Water,light & electromagnetic waves are transverse waves.
9. Coherent waves have same frequency & in phase.
10. As the frequency of a wave increases its energy increases and its wavelength decreases.
11. Shorter waves with higher frequencies have shorter periods.

1. Light is a transverse wave
2. Light slows down, bends toward the normal and has a shorter wavelength when it enters a higher refractive index(n).
3. Medium with higher refractive index has higher optical density.
4. At the critical angle a light wave will be refracted to 90 degrees.
5. Blue light has more energy,a shorter wavelength and a higher frequency than red light (remember- ROYGBIV).
6. Monochromatic light has one color, frequency & wavelength.

1. Water waves moves faster at deeper region. This change in speed causes refraction of water waves.
2. Water waves has longer wavelength at deeper region.
3. Deeper region is less dense than shallow region.
4. Water waves bended towards normal as it moves from deeper to shallow region.
5. After diffraction, water waves amplitude decrease thus its energy decrease as well.However its speed, wavelength & frequency remain constant.

1. Sound is a longitudinal waves.
2. Sound is produced through vibration, thus compressing & stretching the surrounding air molecules.
3. Louder sound has bigger amplitude.
4. Sound with high pitch has higher frequency.
5. The sound that we hear is known as 'audio sound' that has freuency between 20-20khz.
6. Those sound below 20hz is known as infrasound. While sound with frequency beyond 20khz is known as ultrasonic.
7. Sound require medium to travel. It travels fastest in solid> liquid> gas.
8. Sound can't be heard in vacuum
9. Therefore..Starwars' sound effect in outer space is a myth :)

FAST Facts about Speed & Velocity

1. Speed, distance [d], time, and energy (joules) are scalar quantities.
2. Speed is rate of change of distance, i.e = distance/time
3. The gradient of distance-time graph is a speed.
4. Velocity, displacement [s], momentum, force and acceleration are vectors.
5. Velocity is the rate of change of displacement, i.e = displacement / time
6. The gradient of the displacement-time graph is also the velocity.

1. Acceleration is the rate of change of velocity.
2. The gradient of the velocity-time graph is also the acceleration.
3. Zero acceleration also means either the object is at rest or moving at constant velocity.
4. Weight (in newtons) is mass x gravitational acceleration (w = mg). Mass is not weight!
5. Unbalanced forces will produce acceleration, i.e object not in equilibrium
6. Constant velocity and zero velocity means the net force is zero and the forces are in equilibrium
7. The equilibrium forces is equal in magnitude but opposite in direction to the resultant vector.

1. Momentum is a product of mass & velocity.
2. Momentum is conserved in all collision systems.
3. Total momentum before collision = total momentum after collision
4. Rate of change of momentum over time is an impulsive force. ( mv-mu) /t
5. Change in momentum is an impulse (mv-mu)

1. Energy is a work done.
2. Energy is a scalar qty.
3. Energy can't be created or destroyed by human.
4. Energy can only be transformed.
5. Total energy dring the transformation is constant. (Total initial energy = Total final energy)
6. Gravitational potential energy increases as height increases.
7. Kinetic energy changes only if velocity changes.
8. Eleastic potential energy of the spring increases as the extension or compression of the spring increase.
9. The units for power are [joules/sec] or Watt (W).
10. Power is the rate of work done
11. 1 watt is 1 joule of work being done in 1 second.

In responding to unit conversion questions posted by nina in the chat box, my advice is u need to polish your maths basic skills such as conversion & standard form. But in physics,..by now u shud already memorised the power of 10 for prefix like Mega, Giga, kilo, micro & etc.
For example:
Mega = M = 10⁶
kilo = k = 10³

Here some working examples of unit Conversion :
1. 5 kg = 5 (k)g
= 5 (10³ )g
= 5 x 10³ g
( coz k is the prefix for 10³, so just substitute the value of k with 10³)

2. Lets change the unit from km/hr to m/s

7200 kmhr^-2

= 7200 km / hr²

= 7200 x 10³ m

-------- ----

( 60 x 60)² s²

= 5.6 x 10 ^-1 ms^-2

On next example i'll show u step by step how unit m³ is changed to cm³

4. 125 cm³, lets change the unit to m³

125 cm³ = 125( 1cm x 1cm x 1cm ), now we wanna change the unit cm to m,

coz prefix centi (c) means, c=10^-2,so we subst symbol c with 10^-2

= 125( 10^-2m x 10^-2m x 10^-2m)

= 125( 10^-2 x 10^-2x 10^-2) (m)³ see, the unit now changed to metre cube :)

= 125(10^-2) m³

=125 x 10^-6 m³

We can also rewrite it in standard form ,1.25 x 10^-4 m³

If u still unclear with this conversion problems, u can email me at fizbro@gmail.com

Dear all,