1. A 2.05 kg object is held 3 m above the ground. Its potential energy relative to the ground is
A) 8 J.
B) 20 J.
C) 60 J.
D) 80 J.
E) none of the above
2. Which has greater kinetic energy, a car traveling at 30 km/h or another car of 2/3 the mass traveling at 60 km/h?
A) the 30-km/h car
B) the 60-km/h car
C) both have the same kinetic energy