h = 1.5 + 2.5 t -4.9 t^2
when is h = 0?
solve quadratic for t
4.9 t^2 -2.5 t - 1.5 = 0
you could use http://www.math.com/students/calculators/source/quadratic.htm
Note, quadratics have two solutions of course. In this problem if you get a neagative time, that is how long ago it could have passed the floor on the way up :)
v = Vi - 9.81 t = 2.5 -9.81 t
it better be negative because it is headed down when it hits the floor :)
After solving a difficult physics problem, an excited student throws his book straight up. It leaves his hand at 2.5 m/s from 1.5 m above the ground.
A) How much time does it take until the book hits the floor?
B) What's its velocity then?
1 answer
2 answers