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4) A small 0.260 kg particle is released from rest at point A on a track that is one-quarter of a circle with radius 1.60 m as shown. The particle slides down the track and reaches point B with a speed of 4.80 m/s. From point B, it slides on a long level surface a distance of 3.00 m to point C, where its speed is 1.80 m/s. The particle stops at point D, as shown. (a) What is the coefficient of kinetic friction on the horizontal surface? (b) How much work is done on the particle by friction as it slides down the circular arc from A to B? (c) What is the distance between point C and point D? A R =1 1.60 m m = 0.200 kg K 3.00 m B C D