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To get in shape, you head to the local gym to exercise by lifting weights. Using a lat machine (Fig. P5.48), you notice that the wire connected to the bar is run around three different pulleys and is connected to a vertical stack of weights on the other end. The weights move up and down as you pull down on the bar. Suppose you set the machine so that the weight to be lifted is 120.0 lb. When you pull down on the bar, exerting a constant force, the acceleration experienced by the weights is 0.250 m/s2. What tension must exist in the wire connecting the bar and weights under these conditions? Assume the pulleys are massless and frictionless.
FIGURE P5.48
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Physics for Scientists and Engineers: Foundations and Connections
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