Work is defined as a Newton * meter.
Here we have perfectly inelastic collision. Perfectly inelastic collision is type of collision during which two objects collide, stay connected and momentum is conserved. Formula used for conservation of momentum is:

In case of perfectly inelastic collision v'1 and v'2 are same.
We are given information:
m₁=0.5kg
m₂=0.8kg
v₁=3m/s
v₂=2m/s
v'₁=v'₂=x
0.5*3 + 0.8*2 = 0.5*x + 0.8*x
1.5 + 1.6 = 1.3x
3.1 = 1.3x
x = 2.4 m/s
Keep cool by being active at night, whereas some other desert animals get away from the sun's heat by digging underground burrows.
Balance tubes by spacing them equally around the centrifuge and Always balance tubes with other tubes containing a same volume of liquid are right.
If you don't space them out equally, you will have a lot of broken glass to clean up...trust me. The same thing can happen if you don't have equal amounts of liquid in each tube, but it doesn't have to be exactly the same in every one.