Question

10) A 15,000 kg spacecraft is attempting to dock with another spacecraft that is at rest in space (with respect to a fixed for 12 seconds. After the 1" spacecraft docs with the 2nd (whose mass is 20,000 kg) what is their combined velocity? system on orbi), The 1"'spacecraft s diting with a velocity of 2 m/s. The thrusters can apply 400 N of force

Answer 1

Useful data from the question

mass of spacecraft 1 = M1 = 15000kg

mass of spacecraft 2 = M2 = 20000kg

concept required: This question is based on conservation of momentum. So the required equation will be Initial momentum = Final momentum. In the absence of any external forces.

$M1*V1 = (M1+M2)*V2$

or, V2 = $(M1*V1 )/ (M1+M2)$

or V2 = $6/7$

now applying the force of 400 N for 12 sec.

We know that Force * Time = Momentum

Here the applied force will try to slow down the docked structure. So,

final momentum will be 30000- 4800 = 25200

or, final velocity of the spacecraft(docked) will be 25200/35000

= 0.72m/sec    answer