What best describes an impulse acting on an object?

the net force on an object divided by the time of impact
the velocity of an object divided by its mass
the product of an object's mass and the time of force impact
the product of an object's mass and its change in velocity

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.

Patricia is trying to compare the average rainfall of new york to that of arizona. a comparison between these two states for the months of july through september would best be measured in

Which is not true of alpha radiation? o a. it increases the number of protons. o b. it has a positive charge. o c. it causes transmutation. o d. it is heaviest of the three types