A 25-Kg Block on a Horizontal Surface Is Attached to a Light

question 31

Multiple Choice

A 25-kg block on a horizontal surface is attached to a light spring (force constant = 8.0 kN/m) . The block is pulled 10 cm to the right from its equilibrium position and released from rest. When the block has moved 2.0 cm toward its equilibrium position, its kinetic energy is 12 J. What is the change in mechanical energy caused by the frictional force on the block as it moves the 2.0 cm?

• A) −4.0 J
• B) −3.5 J
• C) −2.4 J
• D) −2.9 J
• E) −15 J

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Definitions:

Water Potential

The potential energy of water per unit volume relative to pure water, which determines the direction water will flow.

Tension-Cohesion Model

A theory explaining how water moves through plants, relying on water's cohesive properties and the tension created by transpiration.

Tension-Cohesion Model

A theory explaining the movement of water through the xylem of plants, based on water molecule cohesion and tension created by evaporation.

Water Potential

A measure of the potential energy in water as well as the difference in potential energy between a given water sample and pure water, determining the direction water will flow.