A girl and her bicycle have a total mass of 40.0 kg. At the top of the hill her speed is 5.0 m/s, and her speed doubles as she rides down the hill. The hill is 10.0 m high and 100 m long. How much kinetic energy and potential energy is lost to friction?
A、2 420 J;
B、1 500 J;
C、2 000 J;
D、3 920 J;
E、4 920 J;
F、1 920 J; G:5 120 J; H:1 990 J
发布时间：2025-05-10 22:57:06
