[问答题]
A car maintains a constant sp
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q6d h7ct52hf oey shown in Fig. 5–45. Both the hill and valley have a radius of curvature R. (a) How do the normal forces a
qfo6 d2hh 57ctcting on the car at A, B, and C compare? (Which is largest? Smallest?) Explain. (b) Where would the driver feel heaviest? Lightest? Explain. (c) How fast can the car go without losing contact with the road at A?
