# Math Help - Another Velocity Question

1. ## Another Velocity Question

" A stone is thrown vertically upward from the edge of a building 300 m high with an initial velocity of 10 m/s. Missing the building on the way down, what is the...

A) Time of flight

B) Velocity of the stone before impact with the ground

I've got

D= 300 m
V0= 10 m/s
A= 9.8 m/s^2
T= ?
V= ?

I don't know the formula without those two variables, any help would be greatly appreciated.

2. Originally Posted by Caturdayz
" A stone is thrown vertically upward from the edge of a building 300 m high with an initial velocity of 10 m/s. Missing the building on the way down, what is the...

A) Time of flight

B) Velocity of the stone before impact with the ground

I've got

D= 300 m
V0= 10 m/s
A= 9.8 m/s^2
T= ?
V= ?

I don't know the formula without those two variables, any help would be greatly appreciated.
(a) $\Delta y = v_o t - \frac{1}{2}gt^2$

sub in what you know ... solve the quadratic for t

(b) $v_f^2 = v_o^2 - 2g(\Delta y)$

remember that $\Delta y$ is a vector