The 10 kg block has initial speed of v0 = 2 m/s,at midway between A and B. After hitting spring B, it travels in opposite direction and strikes A. The coefficient of friction is = 0.2. What is the total distance travelled by the block before coming to rest?

1) 7.95 m.
2) 2.35 m.
3) 1.76 m.
4) 6.78 m.
The friction force f = 0.2(10) = 2 N. The friction force being opposite to the motion is negative, also the spring force does negative work as it opposes the displacement.


An assumption is made that the block after bouncing back does not strike the spring 2 again.


As d2 < 8m, the block does not strike spring 2.
Total distance travelled = d1 + d2 = 0.83 + 4.34 = 5.17m.