# Thread: URGENT Geometric Series HELP NEEDED!!!

1. ## URGENT Geometric Series HELP NEEDED!!!

*If you drop a superball which bounces 70% of its height each bounce from a height of 10 feet, how far has it traveled altogether by the moment it hits the floor the fourth time? How far by the 10th time?

2. Originally Posted by cjwcorp

*If you drop a superball which bounces 70% of its height each bounce from a height of 10 feet, how far has it traveled altogether by the moment it hits the floor the fourth time? How far by the 10th time?
Step 1: Draw a picture of the ball bouncing.

Step 2: Label the heights of each bounce.

Step 3: Write down the appropriate sum for total distance bounced.

Step 4: Apply the formula for the sum of a geometric series.

3. Would it be possible to receive more help? I'm not really good at this...

4. It'd be helpful if you provided what you tried as we are here to help guide you.

Just imagine dropping the ball. It will fall down 10 feet. Bounce up 70% of 10 feet (i.e. $\displaystyle .7 \times 10$). Fall back down that same amount. Bounce back up 70% of its previous height (which was $\displaystyle .7 \times 10$) and fall back the same amount again. So on and so on.

You could probably figure out the geometric series for the question and if not, you can always do it the long way and keep going through the process until you get to the 4th and 10th bounce.

5. I don't really know how to draw it... Can you draw it for me?