Soal Latihan dan Jawaban Reading Comprehension 85
The ability of falling cats to right themselves in midair and land on their feet has
been a source of wonder for ages. Biologists long regarded it as an example of
adaptation by natural selection, but for physicists it bordered on the miraculous
Newton’s laws of motion assume that the total amount of spin of a body cannot change
(5) unless an external torque speeds it up or slows it down. If a cat has no spin when it is
released and experiences no external torque, it ought not to be able to twist around as it
In the speed of its execution, the righting of a tumbling cat resembles a magician’s
trick. The gyrations of the cat in midair are too fast for the human eye to follow, so the
(10) process is obscured. Either the eye must be speeded up, or the cat’s fall slowed down
for the phenomenon to be observed. A century ago the former was accomplished by
means of high-speed photography using equipment now available in any pharmacy.
But in the nineteenth century the capture on film of a falling cat constituted a scientific
(15) The experiment was described in a paper presented to the Paris Academy in 1894.
Two sequences of twenty photographs each, one from the side and one from behind,
show a white cat in the act of righting itself. Grainy and quaint though they are, the
photos show that the cat was dropped upside down, with no initial spin, and still landed
on its feet. Careful analysis of the photos reveals the secret: As the cat rotates as the front
(20) of its body clockwise, the rear and tail twist counterclockwise, so that the total spin
remains zero, in perfect accord with Newton’s laws. Halfway down, the cat pulls in its
legs before reversing its twist and then extends them again, with the desired end result.
The explanation was that while no body can acquire spin without torque, a flexible one
can readily change its orientation, or phase. Cats know this instinctively, but scientists
(25) could not be sure how it happened until they increased the speed of their perceptions a
Reading Comprehension 85
Procedures in scientific investigation
The differences between biology and physics.
Miracles in modern science
The explanation of an interesting phenomenon
the righting of a tumbling cat
the cat's fall slowed down
a scientific experiment
The photographs were not very clear.
The photographer thought the cat might be injured.
The photographer used inferior equipment
The purpose of the photographs was to explain the process.
The necessary equipment was easy to obtain.
It was not fast enough to provide new information.
It was a relatively new technology.
The resulting photographs are difficult to interpret.
By studying Newton's laws of motion.
By analyzing photographs
By observing a white cat in a dark room
By dropping a cat from a greater height.