The ball will bounce 72 cm high if dropped from a height of 120 cm
Solution:
Given, The height that a ball bounces varies directly with the height from which it is dropped.
A certain ball bounces 30 cm when dropped from a height of 50 cm.
We have to find how high will the ball bounce if dropped from a height of 120 cm?
Now, according to given information,
When dropped from 50 cm ⇒ bounces 30 cm
Then, when dropped from 120 cm ⇒ bounces "n" cm
Now by Chris cross method, we get,
[tex]\begin{array}{l}{n \times 50=30 \times 120} \\\\ {\rightarrow n=\frac{30 \times 120}{50}} \\\\ {\rightarrow n=\frac{3600}{50}} \\\\ {\rightarrow n=72}\end{array}[/tex]
Hence, the ball bounces 72 cm high.