# Force calculation (not 100% sure what type it is)

1. Oct 5, 2015

### KUphysstudent

1. The problem statement, all variables and given/known data
A spaceship with mass m = 800 kg moves freely in gravitionalfree zone. It moves with a constant velocity v = 1.5 km/s for t < 0. At t = 0 the spaceship is starting to break using a rocket acting on it with a time dependent force F(t) = Bt (T-t), where B is a positive constant, and the spaceship is at rest at T = 240s.

a) Find the constant B

b) Find the spaceships maximum acceleration under breaking

2. Relevant equations
I dont want anyone to solve this for me. Im looking for pointers as to how i approach part (a) of this problem, since I havnt seen anything like it before, as far as i remember.

3. The attempt at a solution
Nothing on papar yet.

The only thing I can think of is P = m a = 1.200.000 (kg*m)/s
The problem is that doesnt help me

Last edited: Oct 5, 2015
2. Oct 5, 2015

### SteamKing

Staff Emeritus
You should draw a free body diagram of the rocket and indicate all of the relevant forces acting on it. Find the net force and use Newton's Second Law of Motion.

BTW, the spaceship is "braking", not "breaking", unless it's flying to pieces.