Acceleration of Space ship with thrust

[mtv]

New to the forum looking for Acceleration of Space ship with thrust

The first stage of a space vehicle consumed fuel and oxidizer at the rate of 1.90 104 kg/s with an exhaust speed of 3.45 *10^3 m/s.


(a) Calculate the thrust produced by this engine.
I got 65550000 N this answer was correct.


(b) Find the acceleration the vehicle had just as it lifted off the launch pad on the Earth, taking the vehicle's initial mass as 3.00* 10^6 kg.
But I am stuck on this question

 

[gneill]

The first stage of a space vehicle consumed fuel and oxidizer at the rate of 1.90 104 kg/s with an exhaust speed of 3.45 *10^3 m/s.


(a) Calculate the thrust produced by this engine.
I got 65550000 N this answer was correct.


(b) Find the acceleration the vehicle had just as it lifted off the launch pad on the Earth, taking the vehicle's initial mass as 3.00* 10^6 kg.
But I am stuck on this question

Be sure to take into account all the forces that are acting on the vehicle. Draw a free body diagram for the instant of launch.