Physics - NLM Question with Solution | TestHub
A 2.0 kg block is attached to one end of a spring with a spring constant of 100N/m and a 4.0 kg block is attached to the other end. The blocks are placed on a horizontal frictionless surface and set into motion. At one instant the 2.0 kg block is observed to be traveling to the right with a speed of 0.50m/s and the 4.0 kg block is observed to be traveling to the left with a speed of 0.30m/s. Since the only forces on the blocks are the force of gravity, the normal force of the surface, and the force of the spring, we can definitely conclude that:
Options:
Answer:
Solution:
The only horizontal forces are the spring forces, which are internal to the system, so the total momentum of the two blocks is constant.
Total momentum at the instant (right positive): .
If the motion had started from rest, the total momentum would be zero for all time. So at least one block was moving at the start. The compression of the spring cannot be concluded from the data.
