This preview shows pages 1–2. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: 7-2) In (d), the quicker way (and the way we really intend the students to go), is to simply use W=-|Fd| and with W from (c) and F from (a) get d. SO IGNORE THE ABOVE CALCULATION BUT GIVE CREDIT IF THEY DO IT THAT WAY 7-3) a) The force of sliding friction always acts in the direction opposite of the velocity relative to the fixed surface (so it will always act to decrease the kinetic energy of a body sliding on a fixed surface). This means the work is always negative. b) If we move against friction in one direction and then move back in the other direction, we lose kinetic energy both ways. If the friction force were conservative, we would expect to lose energy in one direction and gain it back in the other direction. P121 Week 3 Ch. 7 Homework Solutions page 2 of 2 7-4)...
View Full Document