Coal Diver
Everything you wanted to know about coal, but were afraid to ask.
In this first example, there is a picture of a Toyota Prius and one of
the large earth moving machines commonly used in surface coal mining.
While the earth mover may look like an ordinary dump truck, it is
certainly not the size of an ordinary dump truck.
The machine,
a Liebherr T
282B weighs 200 tons empty and can hold 360 tons of coal in a
single load. It is 48 feet long and 24 feet tall, has a wheelbase
of 21 feet. It is powered by a 20 cylinder 3500 horsepower engine,
and has a top speed of 40 mph.
So it's a big truck. But can you figure out how big? Drag the
slider to try and change the size of the Prius so that the scale of
the photos are the same. Once you think you have the answer, press
the button to make your guess.
The picture on the left is too big. Try making it smaller.
The picture on the left is too small. Try making it bigger.
Congratulations! The picture on the left is at the same scale as the one on the right!
While it is difficult to compare the pictures because of the
difference in camera angles, the people standing at the bottom of
each image provide some perspective. With the image of the truck,
the people are in the original. With the car, they've been
photoshopped on top.
What about the raw numbers? The 282B is 24ft tall, and the Prius
is just under 5ft tall, making the 282B almost five times as
tall. Here are the rest of the statistics, according to Wikipedia:

Liebherr T 282B 
Toyota
Prius 
Scale 
Height  24ft (14.5m)  4.9ft (1.49m)  4.9x 
Width  29ft (8.7m)  5.6ft (1.7m)  5.1x 
Length  48ft (14.5m)  14.6ft (4.5m)  3.2x 
Curb Weight  237 tons (empty) 600 tons (loaded)  1.3 tons  182x 462x 
Wheelbase  21.5ft (6.55m)  8.9ft  2.4x 
Cylinders  V20  4  5x 
Displacement  90 litres (5500in^{3})  1.5
litres (92in^{3})  60x 
Power  3500hp  67hp  52x 
Cost  $45M  $37k  108135x 