Một đoàn tàu chạy với vận tốc 72 km/h thì phanh chạy chậm đến sau 10s vận tốc giảm xuống còn 54km/h hỏi sau bao lâu đoàn tàu dừng hẳn

if the thermos has a vacuum innner, then heat through conv currents and conduction are reduced = vacuum flask

answer would be letter choice (a),   a ball resting on a shelf. would be another example of potential energy   >   stored energy > not moving.

a ball spinning on a finger   >   kinetic energy > moving energy

a ball rolling on the ground   >   kinetic energy   > moving energy

a   ball flying through the air   > kinetic energy   >   moving energy

hope that                                         : )

3. dark matter

empty space could also be a simple vacuum