Consider the situation shown in Figure 7.16, where a baseball player slides to a stop on level ground. Using energy considerations, calculate the distance the 65.0-kg baseball player slides, given that his initial speed is 6.00 m/s and the force of friction against him is a constant 450 N.

Strategy

Friction stops the player by converting his kinetic energy into other forms, including thermal energy. In terms of the work-energy theorem, the work done by friction, which is negative, is added to the initial kinetic energy to reduce it to zero. The work done by friction is negative, because is in the opposite direction of the motion (that is, θ=180°, and so cos θ =-1). Thus W_nc = -fd. The equation simplifies to

or

This equation can now be solved for the distance d.

Transcribed Image Text:

f = 450 N