How long will it take for the ball to hit the ground

The last answer choice.

Explanation:

The formula for this situation is . Since you know the inital distance from the ground, and there is not initial velocity, the equation can be rewritten as .

, or the last answer choice. Hope this helps!

see earlier

force is based upon mass and acceleration.the statement is not always true.

it can be explained from newton's second law of motion.

as per newton's second law of motion the rate of change of momentum is directly proportional to the applied force and takes place along the direction of force.

mathematically it can be written as -

                                              ⇒      

here   k is the proportionality constant whose value is 1.

                                                            [a is the acceleration=dv/dt]

hence we see that force not only depends on mass and acceleration but also on velocity and rate of change of mass. force f will depend on mass and acceleration only when mass is constant.

hence the statement that force is based upon mass and acceleration is false.