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Which option accurately describes an unbalanced force?
1.Three rows of cement blocks from a foundation for a house, and the house rests on its foundation.
2.The force of a house pressing down on its foundation of cement blocks is 3,000 N
3.Each cement block supports a 2-N force, but when the foundation is built in a staggered pattern it can support 2,000 N
4.A 2-N force presses down on the cement block at the same time as a 1.5-N force presses up on the cement block