A rocket travels in a trajectory given by the equation s = -4.9t 2 + v0t, where s is meters above ground, t is time in seconds and v0 is the initial velocity. If the intial velocity is 49 m/sec, after how many seconds will the rocket reach its maximum height?

a 5
b 10
c 15

The figure shows triangle def and line segment bc, which is parallel to ef: triangle def has a point b on side de and point c on side df. the line bc is parallel to the line ef. part a: is triangle def similar to triangle dbc? explain using what you know about triangle similarity. part b: which line segment on triangle dbc corresponds to line segment ef? explain your answer. part c: which angle on triangle dbc corresponds to angle f? explain your answer. asap