If the density of the universe is less than the critical density, ...

[gbarreiro]

If the density of the universe is less than the critical density, then the total energy of the universe is
 
  A) zero. B) negative. C) positive.

Question 2

A rocket with a mass of 2.0  106 kg is designed to take off from the surface of the earth by burning fuel and ejecting it with an exhaust speed of 3500 m/s.
 
  What is the minimum rate at which the fuel should be consumed in order to attain liftoff? A)
 
  5.6  103 kg/s
  B)
 
  1.4  103 kg/s
  C)
 
  1.8  103 kg/s
  D)
 
  2.8  103 kg/s
  E)
 
  18  103 kg/s

[Yixagurpuldink]

Answer to Question 1

C

Answer to Question 2

A

[gbarreiro]

Thank you!

[Yixagurpuldink]

Always glad to help...