Two Supports, Made of the Same Material and Initially of Equal

question 20

Multiple Choice

Two supports, made of the same material and initially of equal length, are 2.0 m apart. A stiff board with a length of 4.0 m and a mass of 10 kg is placed on the supports, with one support at the left end and the other at the midpoint. A block is placed on the board a distance of 0.50 m from left end.As a result the board is horizontal. The mass of the block is:

• A) zero
• B) 2.3 kg
• C) 6.6 kg
• D) 10 kg
• E) 20 kg

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Definitions:

Biomass

The total mass of all living organisms in a specific area, habitat, or region.

Weirs

Low dams built across rivers to raise the level of water upstream or regulate its flow for purposes such as irrigation, fish trapping, and water diversion.

Fish Traps

Engineered structures placed in aquatic environments designed to trap fish or other aquatic animals.

Microliths

Small stone tools, typically made by prehistoric peoples, used as spear points or in other sharp implements.