Afixed, single pulley that is used to lift a block does which one of the following? . a.. doubles the force required to lift the block. b.. decreases the force required to lift the block. c.. makes the block easier to lift by changing the direction of the force needed to lift it. d.. decreases the force required and changes the direction of the force required.

A fixed single pulley can't affect the forces. It only changes their directions.

The horse latitudes-high-pressure zones about 30 degrees north and 30 degrees south of the equator.-warm air traveling away from the equator cools and sinks-weather tends to be clear and drythe doldrums-low-pressure near equator-air rises and spreads out toward the poles-rising moist air produces clouds and heavy rainthe westerlies-blow from the west-move from the horse latitudes toward the poles.-bring storms across much of the united statesthe tradewinds-blow from the east-move from the horse latitudes toward the equator  -strong, steady winds