Determine the electrical force of attraction between two balloons with separate charges of + 3.0 x 10^-9C and 9.0 x 10^-9 C when separated a distance of 76 cm.

A. -4.67x10^-17N
B. 1.40x10^-11N
C. -3.19x10^-9N
D. -4.20x10^-7N

If an atom contains 11 protons in its nucleus, predict the element with the atomic number and electronic configuration. will the number of electrons remain the same during the chemical reaction in such an atom? explain.

What’s #16 asking me and how do i solve it?

The man of mass m1 and the woman of mass m2 are standing on opposite ends of the platform of mass m0 which moves with negligible friction and is initially at rest with s = 0. the man and woman begin to approach each other. derive an expression for the displacement s of the platform when the two meet in terms of the displacement x1 of the man relative to the platform.