How far from a concave mirror must an object be placed?

Calculate the work done by an external agent during an isothermal compression of 1.00 mol of oxygen from a volume of 22.4 l at 10∘c and 1.0 atm pressure to 16.8l

What tightening torque should be used for a hexagonal head screw (not split-bolt) on a 250 kcmil conductor?

What is the name for the remnant of an asymptotic giant that has lost its shells? black dwarf white dwarf yellow giant black hole