February 1st, 2011 @3:47 am

Try typing it in utube there are soem great vidoes there maybe something that could help you solve this.

February 1st, 2011 @3:51 am

Just substitute, you’re given everything you need.

h = 1/2 * g * t^2

h = .5 * 980 cm/sec * 20^2 sec

h = 196000 cm s (centimeter seconds)

I think at least, not exactly sure about if it’s 20^2 seconds or (20 seconds)^2, but you get the idea

Just substitute the given values in the formula.