Since the acceleration due to gravity is a constant for all objects, no matter what their mass, that means that all objects fall at the same rate—assuming the effect of air resistance is negligible. This is counterintuitive, since you would expect a heavy object to fall faster than an object that weighed less. But it is a fact. Try dropping two objects at the same time, from the same height, making sure they are heavy enough not to be affected by air resistance. You will see they hit the ground at the same time.
Assuming the balls were dropped from a great enough height to attain their respective terminal velocities the golf ball would hit the ground first. This is because the tennis ball has a larger surface area (and is usually rougher) which means it will create more drag which will cause more air resistance which will result in a lower terminal velocity.
It all depends on from how high you drop them. But you ALWAYS need to take the drag force into account.
Yes both balls will have the same downward acceleration due to the gravitational force, but they will have different upward accelerations due to drag.
F = ma
F = m(g - d) = where d is the upward drag force.
Based on the above, the RESULTANT force on each ball would be different, even if they were the same mass, and the resultant force is what creates the downward acceleration.
It's not as simple as liner equations because drag force varies based on velocity, so some integration would be required.
They would hit the ground at the same time
If you are going to call somebody a MORON at least spell it correctly.
The ball that have more mass or more density will hit the ground first. That is because it will acquire more speed when removed to hit the ground. It is like comparing a bundle of cotton and a bundle of stone.