Một ống dây điện diện tích 10cm°2 , chiều dài 10cm và có 2000 vòng dây. Hệ số tự cảm của ống dây (không lõi, đặt trong không khí ) là bao nhiêu.

Two manned satellites approaching one another at a relative speed of 0.550 m/s intend to dock. the first has a mass of 2.50 ✕ 103 kg, and the second a mass of 7.50 ✕ 103 kg. assume that the positive direction is directed from the second satellite towards the first satellite. (a) calculate the final velocity after docking, in the frame of reference in which the first satellite was originally at rest.(b) what is the loss of kinetic energy in this inelastic collision? (c) repeat both parts, in the frame of reference in which the second satellite was originally at rest. final velocity(d) loss of kinetic energy = ?

Properties seen when one one substance changes to another are known as properties

Could we see a galaxy that is 20 billion light-years away?