Answer:
a
Her mass is

b
The measurement of the astronaut acceleration would be defined by relation

Hence it is affected by the mass of the vehicle, the acceleration of the vehicle and her mass
Now to avoid recoil on the vehicle the force on the astronaut should not be provided by the vehicle
Step-by-step explanation:
From the question we are told that
The net external force is

The astronaut's acceleration

Generally force is mathematically represented as

Where m is the mass of the astronaut
Now making m the subject in order to obtain the mass we have



Now when this force is applied it is both felt by the astronaut and the vehicle
Hence

=>

This means that the measurement of the astronaut acceleration would be defined by relation
