Chap05-Solution2 - Chap.5 HW2 Questions 5. Free-body...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
5 Chap.5 HW2 Questions 5. Free-body diagrams are shown for four situations in which an object is pulled by several forces across a frictionless floor, as seen from overhead. In which situations does the object's acceleration have (a) an x component and Solution (2), (3), (4) For (1) the x components of the forces cancel. (b) a y component? Solution (1), (3), (4) For (2) the y components of the forces cancel. (c) In each situation, give the direction of a by naming either a quadrant or a direction along an axis. (This can be done with a few mental calculations.) (1) along +y, (2) along +x (3) in 4 th quadrant, (4) in 3 rd quadrant 8. Figure 5-27 shows a train of four blocks being pulled across a frictionless floor by force F v . What total mass is accelerated to the right by (a) force F v , (b) cord 3, and (c) cord 1? (d) Rank the blocks according to their accelerations, greatest first. (e) Rank the cords according to their tension, greatest first. a) All mass is accelerated = 20 kg b) All except the first (2 kg) mass, 18 kg c) Only the last mass, 10 kg. d) All blocks have the same acceleration e) 3, 2, 1 Problems 25. Tarzan, who weighs 820 N, swings from a cliff at the end of a 20.0 m vine that hangs from a high tree limb and initially makes an angle of 22.0° with the vertical. Assume that an x axis extends horizontally away from the cliff edge and a y axis extends upward. Immediately after Tarzan steps off the cliff, the tension in the vine is 760 N. Just then, what are (a) the force on him from the vine in unit-vector notation Rope Tarzan θ
Background image of page 1

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

View Full DocumentRight Arrow Icon
6 We need to rewrite the vector T = 760 N, 68 0 above the x -axis in unit vector form ()() () j ˆ N 705 i ˆ N 285 j ˆ 68 cos i ˆ 68 sin j ˆ sin i ˆ cos 0 0 + = + = φ + φ = T T T T T v The net force on him (b) in unit-vector notation, Tarzan is now in mid-air and there are two forces on him, the weight force and the tension in the vine. Thus, ( ) ( ) ( ) j ˆ N 115 i ˆ N 285 j ˆ N 820 - j ˆ N 705 i ˆ N 285 = + = + = g net F T F v v v The net force on him (c) a magnitude and (d) an angle relative to the positive direction of the x axis?
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 04/04/2008 for the course PHYS 213 taught by Professor Oshea during the Spring '08 term at Kansas State University.

Page1 / 5

Chap05-Solution2 - Chap.5 HW2 Questions 5. Free-body...

This preview shows document pages 1 - 3. Sign up to view the full document.

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