A coil spring with a spring rate of 0.28 N / cm is stretched with a force of 1.0 N to a length of 12.0 cm. Calculate the length of the spring in untensioned condition.

What is the specific heat of wood ?

20) what is a magnetic field? 21) in which direction do magnetic field lines always point? 22) sketch a diagram showing how a plotting compass points around a 23) name two magnetic poles that will: a) attract each other b) repel each other. 24) explain why you can use a compass to navigate. 25) what's an electromagnet? 26) list two ways to increase the strength of an electromagnet. 27) the wire in a simple motor feels a force when a current flows through it. why is this? i need answers to check mine

James joule carefully measured the difference in temperature of the water at the top and bottom of a waterfall. why did he expect a difference