I'm not sure about the magnitude, but the direction of the normal force is upward.
Answer: x ≈ 36.3 cm
Explanation:
Conservation of momentum during the collision
0.0340(120) + 1.24(0) = (0.0340 + 1.24) v
v = 3.2025 m/s
The kinetic energy of the block/bullet mass will convert to spring potential
½kx² = ½mv²
x = √(mv²/k)
x = √(1.274(3.2025²) / 99.0)
x = 0.363293... ≈ 36.3 cm
Now I can actually edit my answer directly: I'm fairly sure I've got this wrong, and my mind has gone blank for how to do it, if someone could delete this that would be great and I'll think about it and see if I can figure it out!
Low coefficient of friction
1. flying a plane (friction between air and plane)
2. ice skating (friction between ice and skate blade)
3. swimming (water & skin)
4. rowing a boat (water and boat)