REQUIRED PRACTICAL 9: investigating reflection and refraction

what is the aim?

to investigate specular reflection of a smooth surface

what is the independent variable?

angle of incidence

what is the dependent variable?

angle of reflection

what is the control variable

• distance of ray box from the mirror

• width of the light beam

• same frequency/ wavelength of the light

what is the first step for the practical?

• place transparent rectangular block and a piece of paper and trace around it.

• use a ray box or laser yo shine a ray at the middle of one side of the block

what is the second step?

• trace the incident ray and mark where the light ray emerges on the other side of the block.

• remove the block and with a straight line join up the incident ray and emergent point to show the path of a reflected ray through the block

what is the third step?

• draw the normal at the point where the light ray entered the block

• use protractor to measure the angle between incident ray and normal

what is the fourth step?

• repeat experiment using rectangular block made from different materials, keeping the incident ray the same throughout