Net Force of a Rocket and Acceleration

[icecubefosho]

Homework Statement

An 8.0Kg rocket is fired and encounters a force of air resistance of 4.9N. If the rocket's engines applied 100N of thrust:
A. What is the Net Force on the rocket?
B. What is the Rocket's Acceleration?

Homework Equations

(A) F=MA
(B) Is it (Vfinal - Vinitial)/T?

The Attempt at a Solution

(A)F=MA
F=(8.0KG)(A) = (8.0 x A) The paper tells me its 16.7N
(B) I don't know if this is the right equation... but it must be about 2.9 M/S2 to get A above.

 

[learningphysics]

a) The rocket is fired vertically... just added up all the forces in the vertical direction... remember to take signs into account... you have 3 forces... thrust, gravity and air resistance.

b) here use fnet = ma where fnet is what you get in part a).