Different harmonics can be created by using the same instrument. In this illustration, the tubing shows how different wave lengths can occur from the same tube.
The distance of the image appears at the distance x in the equation (1/distance of focus)-(1/Distance of object)=(1/x). The magnification of the object is equal to (height of the image)/(height of the object). The negative value shows that the image is inverted. The magnification is also equal to -(distance of image)/(distance of object).


When the tailgate is up, an air pocket is formed. This helps the truck to be more aerodynamic. If the tailgate is down, the air current will have higher pressure above the bed, increasing the drag of the truck in motion.