Một học sinh thả 300g chì ở nhiệt độ ở 1000C vào 250g nước ở 58,50C làm cho nước nóng lên đến 600C. Cho biết nhiệt dung riêng của nước c1=4 190J/kg. K a) Hỏi nhiệt độ của chì ngay khi có cân bằng nhiệt? b) Tính nhiệt lượng nước thu vào. c) Tính nhiệt dung riêng của chì. Coi như chỉ có chì và nước trao đổi nhiệt cho nhau.

Is a  vector quantity  that refers to "the rate at which an object changes its position." imagine a person moving rapidly - one step forward and one step back - always returning to the original starting position. while this might result in a frenzy of activity, it would result in a zero velocity. because the person always returns to the original position, the motion would never result in a change in position. since velocity is defined as the rate at which the position changes, this motion results in zero velocity. if a person in motion wishes to maximize their velocity, then that person must make every effort to maximize the amount that they are displaced from their original position. every step must go into moving that person further from where he or she started. for certain, the person should never change directions and begin to return to the starting position.

How are period and frequency related to each other? dperiod is the reciprocal of frequency.