Figure 7-21a shows four situations in which a horizontal force acts on the same block, which is initially at rest. The force magnitudes are F2 = F4 = 2F1 = 2F3. The horizontal component vx of the block’s velocity is shown in Fig. 7-21b for the four situations. (a) Which plot in Fig. 7-21b best corresponds to which force in Fig. 7-21a? (b) Whichplot in Fig. 7-21c (for kinetic energy K versus time t) best corresponds to which plot in Fig. 7-21b?
Figure 7-21 Question 8.
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