The Physics Exam

Hard Data from Victor Lembrey



The following exam was recently given to 200 high school juniors: 100 girls, 100 boys.  Amazingly, all the girls got all three questions right, while all the boys got all three questions wrong.
 
The exam:


 
Newton's first law of motion states that "An object at rest tends to stay at rest and an object in motion tends to stay in motion with the same speed and in the same direction unless acted upon by an unbalanced force," that is, objects "tend to keep on doing what they're doing." In fact, it is the natural tendency of objects to resist changes in their state of motion. This tendency to resist changes in their state of motion is described as inertia.  Inertia is the resistance an object has to a change in its state of motion.


 
At the time, Newton's concept of inertia was in direct opposition to the more popular conceptions about motion. The dominant thought prior to Newton's day was that it was the natural tendency of objects to come to rest. Moving objects, or so it was believed, would eventually stop moving since a force was necessary to keep an object moving. If left to itself, a moving object would eventually come to rest and an object at rest would stay at rest; thus, the idea which dominated the thinking for nearly 2000 years prior to Newton was that it was the natural tendency of all objects to assume a rest position.


 
Galileo, the premier scientist of the seventeenth century, developed the concept of inertia. Galileo reasoned that moving objects eventually stop because of a force called friction. In experiments using a pair of inclined planes facing each other, Galileo observed that a ball will roll down one plane and up the opposite plane to approximately the same height. If smoother planes were used, the ball would roll up the opposite plane even closer to the original height. Galileo reasoned that any difference between initial and final heights was due to the presence of friction and he postulated that if friction could be eliminated entirely, then the ball would reach exactly the same height up the opposite plane.


 
Galileo further observed that regardless of the angle at which the planes were oriented, the final height was almost always equal to the initial height. If the slope of the opposite incline was reduced, then the ball would roll a further distance in order to reach that original height.


 
What is inertia?
a) the resistance an object has to a change in its state of motion
b) me need juicy ass on face right this instant
 
Who developed the concept of inertia?
a) Galileo
b) volleyball cheerleaders

According to Newton's first law of motion, an object at rest tends to stay at rest, and an object in motion…
a) tends to stay in motion
b) tends to look like Heidi Klum's blue tits