A Paddle Wheel Frictionally Adds Thermal Energy to 4

A paddle wheel frictionally adds thermal energy to 4.0 moles of an ideal monatomic gas in a sealed insulated container. The paddle wheel is driven by a cord connected to a falling object as shown in the drawing. How far has the 5.0-kg object fallen when the temperature of the gas increases by 7.50 K?

A) 7.6 m
B) 9.1 m
C) 11 m
D) 13 m
E) 15 m