Which best explains why a washing machine does not represent a closed system? a. water and power come from external sources. b. most washers can use a variety of laundry detergent brands. c. it has multiple cycles, such as wash and spin. d. the amount of wash in a load varies.

A. Water and power come from external sources.

Explanation:

A closed system is a physical system that does not allow for transfer of mass in and out of the system, and is not subject to any net force whose source is external to the system. In this example, we would not be able to consider a washing machine a closed system, as the machine requires water to come in from an external source, which would be a transfer of mass.

c because the action was the roller coaster reaches bottom of hill (action) reaction would be blood tends to drain away from head

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