Ch5 HW3 - Ch5 HW3

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
BRANDON JARROTT FELDKAMP PHYS 2211, section M, Fall 2008 Instructor: Jennifer Curtis Web Assign Current Score: 25 out of 26 Due: Friday, October 3, 2008 09:00 AM EDT Description The Energy Principle: Change of identity; Work done by non-constant forces Instructions Reading: Sections 5.5-5.7 The due date for this assignment is past. Your work can be viewed below, but no changes can be made. 1. [MI2 05.X.22] 2/2 points You push a box out of a carpeted room and along a hallway with a waxed linoleum floor. While pushing the crate 2 m out of the room you exert a force of 26 N; while pushing it 6 m along the hallway you exert a force of 12 N. To bring it to a stop you exert a force of 6 N through a distance of 1.2 m, opposite to the motion. How much work do you do in all? 116.8 117 J Solution or Explanation W = 1 · 1 + 2 · 2 + 3 · 3 Be careful about signs: 3 · 3 = F x 3 x 3 is negative , since the force has a negative x component. 2. [MI2e 5.P.61] 4/4 points A crate with a mass of 50 kg glides through a space station with a speed of 3.5 m/s. An astronaut speeds it up by pushing on it from behind with a force of 220 N, continually pushing with this force through a distance of 5 m. The astronaut moves around to the front of the crate and slows the crate down by pushing backwards with a force of 210 N, backing up through a distance of 3 m. What is the total amount of work done by the astronaut in these two maneuvers? W = 470 470 J After these two maneuvers, what is the speed of the crate? v
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 4

Ch5 HW3 - Ch5 HW3

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online