Q.) A block of mass m=2 kg on a horizontal surface is connected to a spring connected to a wall (see figure). The spring has a spring constant k= 18 N/m. The static friction coefficient between the block and the surface is μs= 0.7 , and the kinetic friction coefficient is μk= 0.3 . Use g=10 m/s2 for the gravitational acceleration.

(a) The spring is initially uncompressed and the block is at position x=0. What is the minimum distance x1 we have to compress the spring for the block to start moving when released? (in meters)

(b) Find the distance |x2−x1| between the point of release x1 found in (a), and the point x2 where the block will come to a stop again. (in meters)

(c) What time t12 does it take the block to come to a rest after the release? (i.e., the time of travel between points x1 and x2; in seconds)