A rocket takes off vertically from the launchpad with no initial ...

[iveyjurea]

A rocket takes off vertically from the launchpad with no initial velocity but a constant upward acceleration of 2.25 m/s2.
 
  At 15.4 s after blastoff, the engines fail completely so the only force on the rocket from then on is the pull of gravity.
  (a) What is the maximum height the rocket will reach above the launchpad?
  (b) How fast is the rocket moving at the instant before it crashes onto the launchpad?
  (c) How long after engine failure does it take for the rocket to crash onto the launchpad?

Question 2

A very large sheet of a conductor carries a uniform charge density of 4.00 pC/mm2 on its surfaces. What is the electric field strength 3.00 mm outside the surface of the conductor? (0 = 8.85  10-12 C2/N  m2)
 
  A) 4.52  105 N/C
  B) 2.26  105 N/C
  C) 9.04  105 N/C
  D) 0.226 N/C
  E) 0.452 N/C

[Benayers]

Answer to Question 1

(a) 328 m (b) 80.2 m/s (c) 11.7 s

Answer to Question 2

A

[iveyjurea]

Wow, this really help

[matt95]

Excellent