# If a ball is dropped on planet Krypton from a height of #20 " ft"# hits the ground in #2" sec"#, at what velocity and how long will it take to hit the ground from the top of a #200 " ft"#-tall building?

##### 2 Answers

#### Explanation:

Let accelaration due to gravity on Krypton be

Hence, when an object at a state of rest is dropped and it reaches ground in

or

or

Let

or

or

or

#### Explanation:

On Krypton, the velocity as a function of time is

The position equation is the anti-derivative of the velocity, so

Let

So, the position equation becomes

When the ball hits the ground, the position will be

You were asked for the time and velocity when the ball hits the ground from

The velocity when