WHICH FORMULA DO I USE AND HOW DO I WORK IT OUT? I SERIOUSLY NEED HELP!
use the formula h=rt-4.9t^2 when h is in meters and h=rt-16t^2.
A rocket is fired upward with an intial speed of 1960m/s. After how many minutes does it hit the ground?
The first formula is for metric units (h is in metres), the second for Imperial units (h is in feet) .
If you live in the US, use the second, if you live elsewhere, use the first.