6th year novmeber exam revision defonitions

Light

Light is a form of energy thst travels away from the source producing it

Reflection of light

The bouncing of light off an object

First law of reflection

the incident ray, the normal at the point of incidence and reflected ray all lie on the same plain

Second law of reflection

i=r

Virtual image

is an image formed by the apparent intersection of rays

Parallax

The apparent movement of one object relative to another due the motion of the observer

Real image

An image formed by the actual intersection of rays

Refraction

The bending of light as it goes from one medium to another

1st law of refraction

The incident ray,the normal at the point of incidence and the retracted ray all lie on the same plane.

2nd law of refraction

Sin i/Sin r=n

Speed

The rate of change of distance in respect to time

Displacement

Distance in a given direction

Velocity

The rate of change of displacement in respect to time

Acceleration

The rate of change of velocity in respect to time

Acceleration due to gravity

In the absence of air resistance all object near the earth’s surface if dropped will fall downward with the same acceleration

Force

Anything that causes the velocity of an object to change

Weight

The force of earth’s gravity working on an object

Newton's first law of motion

Any object in motion or at rest will remain that way unless an unbalanced external force acts on it.

Newton’s second law of motion

When an unbalanced force acts on a body the rate of change of the bodys momentum is directly proportional to the force and takes place in the same direction .