What is the difference between velocity and speed /vector and scalar?

Speed only defines the magnitude of how fast an object is moving from one point to another. This is a scalar quantity (Only Value)

Velocity defines both how fast an object is moving and also in what direction the object is moving. This is a vector quantity (Value + Direction)

choosing tennis and golf balls is your inde choice.

their mass and volume are dep

here we know that ball will drop down by total distance 3.2 m

so here we know that

now using kinematics

now in the same time it will cover horizontal distance of 0.75 m

so speed of the ball will be