They would both hit at the exact same time; if you let them go at the exact same time.
tennis
Both tennis balls will reach the ground at the same time because acceleration due to gravity is constant for all objects regardless of their mass. The only factors that would affect their falling speed would be air resistance, but for a tennis ball and a lead-filled one, the difference in air resistance is negligible.
Tennis has a longer history than golf. The history of tennis, or variations of what would become tennis, dates back to the 12th century. Golf can be traced back to the 15th century.
In baseball, a ground out is an out in which a batter hits a ball on the ground and one of the Infielders catches it before it hits the ground and a ground out can also be an instance of a batter hitting a ball in which an Infielder fields a baseball and then throws to another Infielder in order to record an out as long as the batted baseball was hit on the ground.
According to the laws of physics they would fall at the same rate and land at the same time. However, all variables are not the same. The lightness of the tennis ball would leave it more apt to be affected by winds aloft, including updrafts. Additionally, the fuzzy covering of the tennis ball would make it subject to more wind resistance than the bowling ball, thereby slowing it down more. They would still strike the ground very close together, but the bowling ball would be first.If, however, a bowling ball and a baseball were dropped from the plane, they would strike the ground more-or-less simultaneously.
Tennis ball
Discounting any friction with the air, they would both hit the ground at the same time.
on a tennis court
I would say tennisball because it has less mass inside it.
Because a baseball is smaller you could hit it farther. This is because with less surface area, there is less friction action on the ball. With less friction acting on the ball, it means less "stuff" is holding the ball back from traveling farther, the baseball can physical travel farther than a softball.
it would hit the ground if there was one to hit
In general, yes, but the mass/volume ratios and the surface finishes are different, so the motion would be somewhat more or less pronounced.