A charge of 1.5 C is located at (0, 0 ) and a charge of 2.1 C is ...

[ENagel]

A charge of 1.5 C is located at (0, 0 ) and a charge of 2.1 C is located at (4 m, 0). What is the potential at (4 m, 3 m)?
 
  A)
 
  7000 V
  B)
 
  9000 V
  C)
 
  9000 V at 37
  D)
 
  7000 V at 37
  E)
 
  cannot be determined

Question 2

A rocket of mass M carries a mass m of fuel and starts from rest.
 
  Which method of burning the fuel would result in the greatest final speed of the rocket after all the fuel is burned if the velocity of the exhaust gas relative to the rocket is fixed at uex? A)
 
  Burn the exhaust gas at an exponentially increasing rate until it is exhausted.
  B)
 
  Burn the fuel as slow as possible so the force on the rocket acts for the greatest time resulting in the greatest possible impulse to the rocket.
  C)
 
  Burn the fuel slowly until the rocket reaches a speed equal to uex and then burn the remainder as quickly as possible so that the exhaust gas has the minimum kinetic energy.
  D)
 
  Burn the exhaust gas at an exponentially decreasing rate to make it last forever.
  E)
 
  Burn all the fuel in as short a time as possible.

[amit]

Answer to Question 1

B

Answer to Question 2

E