Thinking about the electromagnet and the horseshoe magnet in the item Electromagnetic field lines , how would the field lines change if the magnet was moved to the side of the electromagnet ? what about closer or farther away ? what if the horseshoe w as replaced by a bar magnet ?

Awater balloon launcher uses an elastic band with a spring constant of 115 n/m to use thee launcher you stretch thee band back with a balloon n it the water balloons have a mass of 1.3 kg a) if you stretch the band by 0.8 m, what elastic force will the band exert? b) with the band stretched 0.8 m, how much elastic potential energy is stored in the spring? c) if you release the band, it pushes forward. what is the kinetic energy of the balloon when it reaches the natural length of the band? d) what is the speed of the balloon when it reaches the natural length of the band?

An object resting on a table weighs 100 n. with what force is the object pushing on the table? with what force is the table pushing on the object? explain how you got your answer.

What is the role of lenses in microscopy?