QUESTION 4 Which of the following is NOT an example of a longitudinal wave?
a. Primary earthquake waves
b. Sounds waves
c. Surface water waves
d. Internal water waves below the surface

I think the answer might be the first one

in simple terms, the principle states that the buoyancy force on an object is equal to the weight of the fluid displaced by the object, or the density of the fluid multiplied by the submerged volume times the gravitational acceleration, g. this is also known as upthrust.

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.