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Predict/Calculate A schoolyard teeter-totter with a total length of 6.4 m and a mass of 41 kg is pivoted at its center. A 21-kg child sits on one end of the teeter-totter. (a) Where should a parent push vertically downward with a force of 210 N in order to hold the teeter-totter level? (b) Where should the parent push with a force of 310 N? (c) How would your answers to parts (a) and (b) change if the mass of the teeter-totter were doubled? Explain.
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