Consider two samples of gas. sample a has pressure p, temperature t and volume v. sample b has pressure p, temperature t/2 and volume v. gas a has the mass of molecule m, gas b has mass of molecule 4m. what is the number of molecules in sample b in terms of number of molecules of sample a, n? (18.5)

Could someone . i have tried to solve myself but my calculation is off

An insulated 40 ft^3 rigid tank contains air at 50 psia and 120°f. a valve connected to the tank is now opened, and air is allowed to escape until the pressure inside drops to 25 psia. the air temperature during this process is kept constant by an electric resistance heater placed in the tank. determine the electrical work done during this process.

If two parallel light rays hit a mirror, they will not be parallel to each other after they reflect.