A rocket of mass M when empty carries a mass M of fuel. The rocket and fuel travel at speed v. The engine of the rocket is fired and all of the fuel is expelled. The speed of the rocket increases
to 2v.

What happens to the kinetic energy of the rocket?
A It doubles.
B It halves.
C It increases by a factor of four.
D It stays the same.

b vvhfvhhhshfehulmv uh to foo is do for uwuwh uh uh uh if uueuegdvshgshe dhshshehwhhesheu dhshshehwhhesheu sushi dydyshyehehwheuwuwe dydyshyehehwheuwuwe dydyshyehehwheuwuwe do do do do the ydhdyuyddhdhdy dydyshyehehwheuwuwe ydhdyuyddhdhdy dydyshyehehwheuwuwe d

the total distance that martina travels that day is

(distance from home to mom's office) plus (distance from mom's office to school)

plus (distance from school to library) plus (distance from library to friend's house)

plus (distance from friend's house to martina's house).

(we don't know what any of these distance actually is.)