Two identical arrows, one with twice the speed of the other, are fired into a bale of hay. Compared with penetration of the slow arrow, the faster arrow penetrates
A)the same distance.
B)two times as far.
C)four times as far.
D)more than four times as far.
E)none of the above

Question

Quizplus · Accepted Answer

The kinetic energy of an object is proportional to the square of its speed. Therefore, if one arrow has twice the speed of the other, it has four times the kinetic energy. The force required to penetrate a bale of hay is related to the kinetic energy of the arrow. Therefore, the faster arrow will penetrate four times as far as the slower arrow.

Two Identical Arrows, One with Twice the Speed of the Other