Question

I know that
0=(20.0m/s)t - 4.90m/s^2)t^2
=t(20.0m/s - 4.90m/s^t)
is equal to t = 4.08 but how do you do that?

Answer 1

0 = 20t - 4.9t
factor
0 = t(20 - 4.9t)
split into 2 equations (b/c zero product property)
t = 0

20 - 4.9t = 0
add 4.9t to both sides
20 = 4.9t
divide by 4.9
4.08 = t

Answer 2

ohh ok thanks