The figure shows a block of mass 2 kg that starts from rest from point A located a height of 480 cm. The track does not offer friction except in the 3 m long section C-D. (?d = 0.25). The block moves down the track, passes through a roller of radius 0.8 m, strikes a spring of constant 120 N/m and compresses it to a length x from its balance position. Consider the acceleration of gravity equal to 10 m/s2 .

Determine:

a) The speed of the block at the highest point of the curl (point B). b) The speed of the block just at the beginning of the rough zone (point C). c) The speed of the block just at the end of the rough zone (point D). d) The length x that the resource is compressed (point E). Answers: a) 8 m/s; b) 9.8 m/s, c) 9 m/s, d) 1.16 m