
Momentum
The mass of gas emitted from the rear of the toy rocket is initially 0.1 kg/s.If the speed relative to the rocket is 50 m/s, and the mass of the rocket is 2 kg.What is the initial acceleration of the rocket?
In this question How can i use the conservation of momentum? Please help>>>>>

Re: Momentum
Using conservation of momentum:
$\displaystyle m_gv_g+m_rv_r=0$
Differentiate with respect to time:
$\displaystyle v_g\frac{dm_g}{dt}+m_r\frac{dv_r}{dt}=0$
Now plug in the given values at time $\displaystyle t=0$, then solve for the acceleration of the rocket $\displaystyle a_r=\frac{dv_r}{dt}$.