@ elena  intro to physics
posted by emilia on .
I posted this question earlier and thank you for respnding, but the answer you give me was incorrect. I try looking at hw you solve and cant find the mistake but when when I check your answer it said it was wrong. Can you please look over it again, I greatly appreciate it
a toy rocket moving vertically upward passes by a 2.2m high window whose sill is 7.0m above the ground. the rocket takes 0.17s to travel the 2.2m height of the wondow
part a): what was the launch speed of the rocket ? assume the propellant is burned very quickly at blastoff
part b) how high will the rocket go ?

What is the correct answer? I'll try to understand where is the mistake.

I‘ve found the mistake
h(o) = v(o)•t  g•t^2/2,
2 h(o) = 2 v(o)•t  g•t^2
v(o) = h(o) /t +gt/2 = 2.2/0.17 + 9.8•0.17/2 = 13.77 m/s.
Then try to calculate yourself…