A concave mirror is to form 0.5m long image of a 5mm lamp filament on a screen 5m from the mirror. What is the distance at which the filament is to be placed in front of the mirror?

Calculate the heat capacity per object when the total energy is 4 quanta. (think of this in terms of increasing from 3.5 quanta of energy in the system to 4.5 quanta of energy in the system, if that were possible.) c4 = __ j/k/object

The vapour pressure of benzene is 53.3 kpa at 60.6 °c, but it fell to 51.5 kpa when 19.0 g of a non-volatile organic compound was dissolved in 500 g of benzene. calculate the molar mass of the compound.

You can decrease the resistance of a length of wire by