5: Two masses, 4 kg and 9 kg respectively, are attached to opposite ends of an ideal spring. The system sits on a frictionless table. If I push the masses together (against the spring) and release the
system, then I find the 4 kg mass has a speed of 3 m/s
A:
What is the speed of the 9 kg mass after release?
B:
What was the amount of energy stored in the spring before release?
C:
Suppose repeat this experiment on a table with friction.
Would the momentum be conserved
why or why not?
Would the energy of the system be conserved why or why not?

Thomas his older brothers, who own a junk yard, on the weekends to earn extra money. he likes to them push broken-down cars to the back of the junk yard because it makes him feel strong. last saturday, they pushed three cars with different weights, and he noticed he used different amounts of force for each one. the cars were the following weights: white car: 2,700 kg red car: 1,500 kg blue car: 2,100 kg think about how much force is needed to move each car. which correctly lists the cars in order from the most to least amount of force needed to move them? a) white, blue, red b) blue, red, white c) red, white, blue d) white, red, blue