How do leptons differ from hadrons?

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

Two identical stars with mass m orbit around their center of mass. each orbit is circular and has radius r, so that the two stars are always on opposite sides of the circle. (a) find the gravitational force of one star on the other. (b) find the orbital speed of each star and the period of the orbit. (c) how much energy would be required to separate the two stars to infinity?

which statements describe the image? check all that apply.the wood is releasing argon gas.this information is useful for dating ancient rock.the process works only with organic matter.the element has a half-life of 5,730 years.this shows the half-life of carbon-19.