Why is 3-D printing considered additive manufacturing? * It manufactures small objects.
It builds objects out of plastic.
It is a new way to manufacture objects.
It creates objects by adding layers.

Awater-filled u-tube manometer is used to measure the pressure inside a tank that contains air. the water level in the u-tube on the side that connects to the tank is 5 ft above the base of the tank. the water level in the other side of the u-tube (which is open to the atmosphere) is 2 ft above the base. determine the pressure within the tank.