describe how light reflecting from a mirror can produce an image. In particular, explain how mirrors can produce images that are larger or smaller than life size, as well as upright or inverted.

A larger image is produced when   >

A smaller image is produced when <

An upright image  is produced when m is positive

An upright image  is produced when m is negative

Explanation:

The mirror equation is given as follows;

For concave mirrors, f = focal length

= Image distance from the mirror (-ve = Image is behind the mirror +ve = Image is in front of the mirror)

= Object distance from the mirror (-ve = Object is behind the mirror +ve = Object is in front of the mirror)

m = Magnification (-ve m = Inverted image +ve m = upright image)

= Image height

= Object height

f = Focal length of the mirror

To produce a larger image >

To produce a smaller image <

To produce an upright image, m should be positive hence, will be negative or the image will appear behind the mirror

To produce an inverted image, m should be negative hence, will be positive or the image will form in front of the mirror.

need to see circuit to get time constant

when a device is used in a circuit in which the voltage is 81 v, the current flowing through the device is 3 a. what is the resistance of the device?

a. 27 ω

b. 40.5 a

c. 243 ω

d. 243 a

the correct answer is a. 27