Answer:The mass of ball B is 10 kg.
Explanation;
Mass of ball A = 
Velocity of the ball A before collision:
Velocity of ball A after collision=
Mass of ball B= 
Velocity of the ball B before collision:
Velocity of ball B after collision=



The mass of ball B is 10 kg.
The total work is
(mass of the elevator, kg) x (9.8 m/s²) x (9.0 m) Joules .
The cat has a speed. The truck and the bicycle both have velocity. We can't be sure of what the plane has.
Well there are a couple ways.
1: The easiest, plant cells have a cell wall or extra protection. You will not find this on an animal cell, as there is only a membrane.
2: Chloroplast. This also will not be found in animal cells as they produce the plant's green color as well as the sugar.
Hope this helps!