I have a hard time conceptualizing string tension, and hence calculating it. For a hypothetical situation, there is a massless string connecting two blocks on a flat, frictionless surface. Block A is 5 kg, block B is 3 kg. There is a string attached to the outside of Block A, and a force of 150 N is applied to this string.(so the outside string pulls block A, which pulls the middle string, which pulls Block B) This is not a homework problem that i know of at all, I just need to conceptualize and calculate tension in a simple situation, and then I should be able to apply to other situations too. Thank you everyone!