Answer:
f = 5 cm
Explanation:
using the thin lens equation, given as follows:

where,
f = focal length = ?
do = the distance of object from lens = 20 cm
di = the distance of image from lens = 6.6667 cm
Therefore,

<u>f = 5 cm</u>
Answer:
I feel like to demonstrate you would use an elastic band as the material. You obviously have to put force in order to see how far it stretches. From this you can also find about its resistance and durability
Also you have to make sure the distance between the two hands are equal as you want an accurate result.
Answer:
Object distance means what is the distance between pole and object. Image distance means when image is formed then the distance between pole and image is called image distance. Focal length is the distance between pole and the principal focus of the mirror.
A lens is a clear object, usually made of glass or plastic, which is used to refract, or bend light. Lenses can concentrate light rays (bring them together) or spread them out. Common examples of lenses include camera lenses, telescope lenses, eyeglasses, and magnifying glasses. Lenses are often double lenses, meaning they have two curved sides. A convex lens is rounded outward, while a concave lens curves inward. (A great way to remember this is that a concave lens creates an indent like a cave!)
The image distance can be calculated with the knowledge of object distance and focal length with the help of lens formula. In optics, the relationship between the distance of an image (i), the distance of an object (o), and the focal length (f) of the lens are given by the formula known as Lens formula. Lens formula is applicable for convex as well as concave lenses. These lenses have negligible thickness. It is an equation that relates the focal length, image distance, and object distance for a spherical mirror. It is given as,
1/i + 1/o = 1/f
i= distance of the image from the lens
o= distance of the object from the lens
f= focal length of the lens
Explanation:
Hope it is helpful....
Answer:
650 km/hr
Explanation:
Draw a right triangle from (0.0) (Point A) down 30 degrees and to the right for a length of 750 (Point B). Then draw a line from B up to the x axis to make a right angle (Point C). Use the cosine function to find line AC, the vector portion of AB that lies of the x (East) axis. Cosine(30)= Adjacent/Hypotenuse.
Cos(30) = AC/750
750*(cos(30)) = AC
AC = 649.5 km/hr