1in the early days of space flight it was important to put a satellite into orbit with spin, but then to remove the spin once it got there. without fancy propulsions systems, the following idea worked rather well: two cables with attached masses were placed on either side of the satellite. the cables were wound around the satellite and the weights initially secured. on a signal, the weights would be released so as to unwind (as the satellite spins) until the ends of the cables unhook and each weight flies away into space (with its unhooked cable behind it). why did it work and how?

Researchers determine that the biodiversity in a woodland region is declining. they identify two major threats to the region's biodiversity, a method to address each threat, and the expected outcome of each method. this information is shown in the table. a) reforestation would not benefit many species because most forest species live on the ground. b) reforestation would take the longest time to be effective because trees take several years to grow. c) biological augmentation would benefit only a few species because is is typically not very effective. d) biological augmentation would take less time to ve effective because it targets the majority of prey species.

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.

Often called simply "velocity," this is the velocity of an object at a particular moment in time.