9781118230725.pdf

7-3 WORK DONE BY THE GRAVITATIONAL FORCE 155 Calculations: We relate the speed to the work done by combining Eqs. 7-10 (the work ...

156 CHAPTER 7 KINETIC ENERGY AND WORK Work Done by the Gravitational Force We next examine the work done on an object by the gra ...

7-3 WORK DONE BY THE GRAVITATIONAL FORCE 157 If the displacement is vertically downward (Fig. 7-7b), then f 0 and the work don ...

158 CHAPTER 7 KINETIC ENERGY AND WORK Sample Problem 7.05 Work done on an accelerating elevator cab An elevator cab of mass m50 ...

7-4 WORK DONE BY A SPRING FORCE 159 Work Done by a Spring Force We next want to examine the work done on a particle-like object ...

160 CHAPTER 7 KINETIC ENERGY AND WORK state. For this common arrangement, we can write Eq. 7-20 as Fxkx (Hooke’s law), (7-21) ...

161 Caution:If the block is not stationary before and after the displacement, then this statement is nottrue. Work Wsis positive ...

162 CHAPTER 7 KINETIC ENERGY AND WORK Work Done by a General Variable Force One-Dimensional Analysis Let us return to the situat ...

7-5 WORK DONE BY A GENERAL VARIABLE FORCE 163 Figure 7-12(a) A one-dimensional force plotted against the displacement xof a part ...

164 CHAPTER 7 KINETIC ENERGY AND WORK Sample Problem 7.07 Work calculated by graphical integration In Fig. 7-13b, an 8.0 kg bloc ...

7-5 WORK DONE BY A GENERAL VARIABLE FORCE 165 Additional examples, video, and practice available at WileyPLUS 2 0  20 40 46 046 ...

166 CHAPTER 7 KINETIC ENERGY AND WORK KEY IDEA The force is a variable force because its xcomponent de- pends on the value of x. ...

167 The instantaneous powerPis the instantaneous time rate of doing work, which we can write as (instantaneous power). (7-43) Su ...

168 CHAPTER 7 KINETIC ENERGY AND WORK Calculation: We use Eq. 7-47 for each force. For force , at anglef 1  180 to velocity , ...

QUESTIONS 169 Fx F 1 –F 1 x (^1) x (a) Fx F 1 –F 1 x (^1) x (b) Fx F 1 –F 1 x (^1) x (c) Fx F 1 –F 1 x 1 x (d) Figure 7-18 Quest ...

170 CHAPTER 7 KINETIC ENERGY AND WORK 6 Figure 7-19 gives the xcom- ponentFxof a force that can act on a particle. If the partic ...

PROBLEMS 171 much like a stone skipped across water. The accompanying fireball was so bright that it could be seen in the daytim ...

172 CHAPTER 7 KINETIC ENERGY AND WORK of magnitude 20.0 N is applied to a 3.00 kg psychology book as the book slides a distance ...

PROBLEMS 173 a (m/s 2 ) as 0 x(m) 0 2 4 6 8 Figure 7-38Problem 34. Figure 7-40Problem 37. h x T x 2 x 1 y Figure 7-41Problem 42. ...

174 CHAPTER 7 KINETIC ENERGY AND WORK end of the cord is pulled over a pulley, of negligible mass and friction and at cord heigh ...