Hi, I know Im not suppsoed to do 2 questions per forum however I dont know the difference between these two problems and why the calculation process at the end is different from each other.
1) A tennis ball is shot vertically to a height of 20 feet and aloowed to drop. Each bounce is 80% as high as the previous bounce. What is the total distance the ball travels from when it is shot unit it bounces the fourth time?
2) Suppose you drop a tennis ball from a height of 15 feet. After the ball hits the floor, it rebounds to 85% of its previous height. What is the total distance the ball traveled.
Hi Jenny
1) A tennis ball is shot vertically to a height of 20 feet and aloowed to drop. Each bounce is 80% as high as the previous bounce. What is the total distance the ball travels from when it is shot unit it bounces the fourth time?
0.8*20=16
0.8*16=12.8
etc
so
Up distance = 20+16+12.8+..... sum to infinity
down distance = 20+16+12.8+ ....sum to infinity
add them together
2) Suppose you drop a tennis ball from a height of 15 feet. After the ball hits the floor, it rebounds to 85% of its previous height. What is the total distance the ball traveled.
15*0.85=12.75
12.65*0.85=10.8375
down distance = 15+12.75+10.8375+ ... sum to infinity
up distance = 12.75+10.8375+.... sum to infinity
add them together
use GP sum of infinite series to get the first answers.
Is that enough help?