You and a friend have some pvc pipes of various lengths and a hacksaw. You select a 2.0 m long section of pipe that is open at both ends but your friend chooses a 0.60 m long section of pipe that is closed at one end. You want to cut your open pipe to a length that makes its no = 2 harmonic the same frequency as the closed-at-one-end pipe’s nc = 3 harmonic. How long should you make your pipe?

two charges are fixed in place on the x-axis as shown. the charge at x = 0 is negative and has magnitude q = 2 μcoulombs (1 μcoulomb = 10-6 coulombs). the charge at x = d, (d = +12 cm), is positive and has magnitude q = 4 μcoulombs. find a point x = xo along the x-axis at which the electric field is zero.

fgravity=10x10=100n case 1

fgravity=30x20=600n case 2

6 times more

a and b sometimes have a positive value