How do you do this problem?

Question

A 134m tall Detroit dept. store building was destroyed by controlled implosion in 1998. Use the formula d=5t squared + vot to estimate how long it took for a piece that broke away from the troof to reach the ground

Answer 1

Now in kinematics we have..
any object which is thrown from a height 'h' the timetaken to reach the ground is
t=square root of (2h/g)...since the object falls down under gravity...
here applying the same we have the height as 134 m.And the time taken by a piiece at the top roof of the building to reach the ground is given by,
t=squareroot of (2*134/9.8)...since g=9.8 m/s2
Hence it simplifies to 5.229 secs...
I hope u understand nd u got the solution..
ALL THE BEST...!!!

Answer 2

Assuming the piece of the roof just fell, since you provided no value for v0, you have

0 = -16t² + 0•t + 134 (where'd you get 5t? that would be negative gravitational attraction)
134 = 16t²
8.375 = t²
2.894 = t

Of course, if the planet you're sending to Yahoo!Answers from has about 1/3 of earth's gravity, then the 5 would be appropriate, and you'd have

134 = 5t²
26.8 = t²
5.18 = t