Force between two identical short bar magnets whose centres are part is 4.8 n when their axes are in same line. if this separation is increased to 2r metre the force between them is reduced to

Consider a system to be two train cars traveling toward each other. what is the total momentum of the system before the train cars collide?   kg • what must the total momentum of the system be after the train cars collide?   kg •  

When is a current produced? when the terminals of an electrochemical cell are connected by a wire if the electric circuit is opened in an electrochemical cell if the electrolyte is removed from an electrochemical cell when the electrodes are reversed in an electrochemical cell

How does an observation about an object differ from an inference about that object