Homework Help: math

Posted by lisa on Tuesday, January 13, 2009 at 8:03pm.

the height that a ball bounces varies directly as the height from which it is dropped. A ball dropped from a height of 20cm bounces 16cm

a) Find the height of the bounce if the ball is dropped from a height of 280cm

b) Find from waht height the ball was dropped if it bounces to a height of 120cm

Thanks in advance.

math - Reiny, Tuesday, January 13, 2009 at 10:42pm
let h be the new height, let x be the height it was dropped from, then

h = kx, where k is a constant
when x=20, h=16
so 16=k20
k = 16/20 = 4/5
then h =4x/5

a)when x= 280
h = 4(280)/5 = 224

b) when h = 120
120 = 4x/5
600 = 4x
x = 150

Answer this Question

Related Questions

math - when a ball is dropped, it bounces back up 4/5 of the height from the ...
calculus - A ball has bounce coefficient 0 < r < 1 if when it is ...
science - Science Experiment Determine a mathematical modelwhich describes the ...
11 - A ball is dropped vertically from height of 30 meters after bounces.The ...
Physics - A ball is dropped from an undetermined height and bounces to 5 meters...
maths lit - a ball is dropped from a height of 2r1/3 meters. It bounces to 3/4 ...
physics - A round ball bounces to 2m after being dropped from an undetermined ...
math - A rubber ball is dropped from an unknown height. It bounces back to 60% ...
math - a ball is dropped from a height of 3m and bounces on the ground . At the ...
math - a ball is dropped from a height of 5m. after each bounce, the ball rises ...

For Further Reading

First Name:
School Subject:
Answer: