## Refraction Of Light

Refraction of light is the change in direction (bending of light rays) when it passes from one optically transparent medium to another. Terms used in refraction: Refracted ray is the bent ray as a result of passing from one optical medium to another. Normal is an imaginary line perpendicular to the interface of media where the refraction occur. Angle of …

## Drawing ray diagrams for plane mirrors

This is a short tutorial on how to draw ray diagrams for plane mirrors. Click on the images to view a larger version. Initially, we have an object in front of a plane mirror. First, we draw an image of the object on the other side of the mirror Distance A is equal to distance B and the image size …

## I/V characteristic graphs For O Level

Metallic conductors at constant temperature The I-V graph of metallic conductor is a straight line pass through the origin. They obey Ohm’s Law, having resistance that is independent of current. (Ohmic conductors) Reason: Resistance in metal is the reduction of the drift velocity of electrons due to collision with the lattice ions. If the temperature of the conductor is kept constant, …

## Acceleration

Acceleration of an object is the rate of change of velocity with respect to time. SI unit is metre per second square or metre per second per second ($m \, s^{-2}$) Vector quantity $a = \frac{v – u}{t}$, where v is final velocity, u is initial velocity and t is time taken. If the velocity of an object increases, …

## Speed vs Velocity

To understand the difference between speed and velocity, you will need to grasp the difference between distance and displacement, which can be found here. Speed is the distance moved per unit time. SI unit is metre per second ($m \, s^{-1}$) Scalar quantity Equation: $\text{Speed} \, = \, \frac{d}{t}$, where d is distance travelled and $t$ is time taken Average …

## Distance vs displacement

Distance travelled by an object is the length of path taken. SI unit is metre (m) Scalar quantity Can never be negative and distance travelled will never decrease Displacement is the shortest distance from the initial to the final position of an object. SI unit is metre (m) Vector quantity Can be negative Distinguishing Between Distance and Displacement If you …

## Speed, Velocity and Acceleration (O Level)

This topic covers “Speed, Velocity and Acceleration” of O Level Physics. (Equivalent to American high school diploma) If this is too basic for you, you can try the more advanced version here. Sub-Topics: Distance vs Displacement Speed vs Velocity Acceleration Equations of Motion Reading Kinematics Graphs Quiz: Practice MCQs For Speed, Velocity & Acceleration