a drum crane whirlwinds in 100m of cable when raising a load of 240N through a height of 10m an effort of 30 000 N is needed Calculate the efficiency showing how you obtained your answer

An automobile of mass 2000 kg moving at 30 m/s is braked suddenly with a constant braking force of 10000 n. how far does the car travel before stopping?

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.

Achlorine atom has 17 protons and 18 neutrons. what is its mass number? what is its atomic number?