Final speed after collision with the wall

before collision the speed of ball initially

time taken for the collision

now as per the formula of acceleration we know that

now plug in all values in it


so acceleration is - 5 m/s/s for above situation
Density = mass divided by volume so if you use that formula Liquid A turns out to be a higher density so it flows slower.
No. The forces of gravity between them would remain unchanged after those three changes.
0.0605J is your answer. Use the formula KE=1/2mv^2