1) Size of the image: 2 cm
In order to calculate the size of the image, we can use the following proportion:

where
p = 80 m is the distance of the tree from the pinhole
q = 20 cm = 0.2 m is the distance of the image from the pinhole
= 8 m is the heigth of the object
is the height of the image
By re-arranging the proportion, we find

2) Magnification: 0.0025
The magnification of a camera is given by the ratio between the size of the image and the size of the real object:

so, in this problem we have

Answer:

Explanation:
Given:
- thickness of the base of the kettle,

- radius of the base of the kettle,

- temperature of the top surface of the kettle base,

- rate of heat transfer through the kettle to boil water,

- We have the latent heat vaporization of water,

- and thermal conductivity of aluminium,

<u>So, the heat rate:</u>


<u>From the Fourier's law of conduction we have:</u>


where:
area of the surface through which conduction occurs
temperature of the bottom surface

is the temperature of the bottom of the base surface of the kettle.
Answer:
26036485.6433 W/m²
Explanation:
E= Energy = 470 J
t = Time = 4 seconds
d = Diameter = 2.6 mm
Power is given by

Intensity is given by

The intensity of the laser beam is 26036485.6433 W/m²
The object that goes through chemical change, changes completely to where you can not change it back to its original form. Physical change you can undo