What is the speed of a missile that travels north
8000 meters in 10.12 seconds?

the independent variable, or the one that is intentionally manipulated is the speed.

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

i think they are all correct

explanation:

they seem good

d) physical means can be used to separate the components of air.