# Calculate missing mass from given impulse

1. Jul 12, 2004

### siemieniuk

hey all... really struggling with how to attack this question:

On September 12, 1966, a Gemini space craft piloted by astronauts Conrad and Gordon met and docked with an orbiting Agena launch vehicle. With plenty of fuel left in the spacecraft, NASA decided to determine the mass of the Agena. When coupled, Gemini's motor was fired, exerting a constant thrust of 890 N for 7 s. As a result of that little nudge, the Gemini-Agena sped up by 0.93 m/s. Assuming Gemini's mass as a constant 34 x 10^2 kg (3400 kg), compute the mass of the Agena.

- I managed to calculate the impulse as 6230 N-s, which causes a momentum change of 6230 kg-m/s. where do I go from here??

thanks

2. Jul 12, 2004

### AKG

$$\Delta p = Mv_2 - Mv_1 = M\Delta v = 0.93M$$

Solving for the mass of Agena should be simple from here; note that M is the combined mass of the system.