Tại tâm của một dòng điện tròn cường độ 5 (A) cảm ứng từ đo được là 31,4.10-6(T). Tính đường kính của dòng điện đó.

Which of the following is considered to be a vector?               a.  temperature    b.  velocity    c.  time    d.  mass

The ballistic pendulum was invented in 1742 by english mathematician benjamin robins. it consists of an initially stationary pendulum that moves after being struck by a bullet, and it is used to measure the original velocity of the bullet. the known variables are the bullet's mass m, the pendulum's mass m, and the height to which the block and bullet swing, determined by the length of the pendulum l and final angle θ. two principles of physics are necessary to solve for the bullet's original velocity. what are these principles? conservation of momentum and newton's third law conservation of energy and conservation of angular momentum grade summary deductions 0% potential 100% conservation of momentum and newton's second law. newton's second law and conservation of angular momentum. conservation of energy and newton's third law conservation of momentum and conservation of angular momentum. conservation of momentum and conservation of energy conservation of energy and newton's second law.

A175 g lump of molten lead at its melting point (327 c) is placed into 55.0 g of water at 20.0 c. the specific heat of lead is 130.j/kg c and the hf of lead is 20,400 j/kg. when the lead and the water have reached equilibrium, what is the temperature of the mixture?