A rocket is fired in a gravity-free environment in deep space. ...

[Lisaclaire]

A rocket is fired in a gravity-free environment in deep space. The rocket has an initial mass of 8000 kg and ejects gas with a velocity of 2000 m/s. How much gas must be ejected in the first second to give the rocket an acceleration of 30.0 m/s2?
 
  A) 120 kg
  B) 7.50 kg
  C) 15.0 kg
  D) 12.0 kg
  E) 150 kg

Question 2

Which one of the following is the correct expression for the energy of the photon?
 
  A) E = h/f
  B) E = h/c
  C) E = hc/
  D) E = c/h
  E) E = h

[tsternbergh47]

Answer to Question 1

A

Answer to Question 2

C

[Lisaclaire]

Wow, this really help

[ecabral0]

Thanks for the timely response, appreciate it