PLS HELP
How can Coulomb's law be used to predict how particles will behave when near each other

Ahorizontal wire is tied to supports at each end and vibrates in its second-overtone standing wave. the tension in the wire is 5.00 n, and the node-to-node distance in the standing wave is 6.28 cm. (a) what is the length of the wire? (b) a point at an anti- node of the standing wave on the wire travels from its maximum upward displacement to its maximum downward displacement in 8.40 ms. what is the wire's mass?

John throws .4 kg ball with velocity of 18 m/s. hits .2 kg bottle and bottle flies 25 m/s. how fast is ball traveling after hitting the bottle?

Find the magnetic field a distance r from the center of a long wire that has radius a and carries a uniform current per unit area j in the positive z direction.