The problem involves calculating the initial velocity of an arrow that penetrates a bale of hay, given its mass, penetration distance, and the average frictional force acting on it. The subject area relates to dynamics and energy principles, particularly the kinetic energy-work theorem.
Some participants have provided guidance on using the work-energy principle, noting that the work done by the frictional force is negative due to the decrease in kinetic energy. There is an ongoing exploration of the implications of this theorem in the context of the problem.
Participants are navigating through the implications of the given values and the assumptions related to the frictional force and the motion of the arrow. There is a focus on understanding the relationship between work and energy without reaching a definitive conclusion.
lking226 said:is the kinetic energy-work theorem net work = change in kinetic energy?
so then, w = 1/2mvf^2-1/2mvi^2, but vf is 0 because the arrow is stopped in the hay so really w = -1/2mvi^2. does that stay negative?