Một dây chì có đường kính tiết diện ngang 1,2 mm. Nếu mật độ dòng điện giới hạn của chì là 450 A/cm2 sẽ thì cường độ dòng điện giới hạn chạy qua dây chì này là bao nhiêu?

Calculate the kinetic energy of earth due to its spinning about its axis. krot = j compare your answer with the kinetic energy of the orbital motion of earth's center of mass about the sun. assume earth to be a homogeneous sphere of mass 6.00 1024 kg and radius 6.40 106 m. the radius of earth's orbit is 1.50 1011 m.

The heliocentric and the geocentric models of the solar system included these central principles

Arailroad car collides with and sticks to an identical railroad car that is initially at rest. after the collision, the total kinetic energy of the two cars is a) the same as before. b) half as much as before. c) one third as much as before. d) one fourth as much as before. e) twice as much as before.