Question

A ball is thrown horizontally from a platform so that the initial height of the ball is 6.0 m above the level ground below. The ball lands 24 m from its original horizontal location. Find how fast the ball was thrown. Show all work.

Can you please explain this step by step? I need to understand this, and how its worked out.

Answer 1

I think the first thing you need to do is find out how long it takes the ball to reach the ground since we know that if you drop a ball from that height, vs. this situation.....both balls would hit the ground at the same time

Answer 2

Do you know the answer to the problem already?

Answer 3

Okay that makes more sense, thank you. :) But I'm not sure how to work out the answer to this problem. What formula would work for this? I'm guessing it's going to be a kinematic equation, but I don't know which one or where to start.

Answer 4

Well without doing the work, my take on it just looking at it and thinking about what to do would be to find the time it takes to reach the ground (which would be one of the kinematic equations but in the y direction).....that time would be the same time that you would need to use to find the initial velocity in the x direction (which you would need a kinematic equation for in the x direction)

Answer 5

And it's been awhile since i have looked at the kinematic equations, but you would need the 2 dimensional kinematic equations for this

Answer 6

Okay thank you! I can look over the kinematic equations in my lesson again, but I just need to know the order of what i need to find first, second, third, etc. You said I would need to find out the time it takes to reach the ground first. What do you think I would need to find next? And after that?

Answer 7

Well lets see I was thinking that once you find the time it takes for the ball to reach the ground in the y direction, you can use that value for your equation for the ball in the x direction....since they both have to be the same in this situation....and since you have the time for the x direction and the distance in the x direction (that includes the initial x position and the final x position) then I think you can solve it

Answer 8

Again I haven't done the calculation so it might not go as smoothly as that but trying to think it out in my head....that's what i believe you need to do

Answer 9

Well I found a few equations, but they involve displacement and initial/final velocity. Final velocity would be zero, I know that, but I am not so sure about initial velocity. Since the ball ended up 24 meters from its original horizontal location, would that be the displacement? or does the 6 meters have a part in the displacement too?

Answer 10

Oh man sorry I didnt see you answered back

Answer 11

Well im assuming that if you are using 2 dimensional kinematics that the displacement would be the position or rather the total amount that the ball moves in either direction where the x displacement would be the 24 and the y displacement would be the 6

Answer 12

http://tatania.phsx.ku.edu/Phsx114/images/Kinematics.jpg

Answer 13

Those are the equations I am looking at right now

Answer 14

Thank you so much for your help! I finally figured out what to do and got the answer. :)

Answer 15

No problem :) I'm glad I could help