they tell you that its the astronaut looking back at earth, he will see the earth spinning slower, thus time going slower on earth relative to him ... :)
3) Calculation:
8 x 10^7 N is the resultant force
since F = m.a, after 30s:
m(rocket) = (2000x10^3) - (1500x30) kg
= 1955000 kg
= 1.96 x 10^6 kg
:. acceleration of rocket = F/m
:. a = (8 x 10^7)/(1.95 x 10^6) m/s^2
For the 85kg astronaut...
1) i got D
because when e/m radiation travels through glass the speed is different, thus causing the spark length to shorten ... i think ... tell me if wrong