A 20-Kg Block Slides Down a Plane (Inclined at 40° with with the Horizontal)

question 46

Multiple Choice

A 2.0-kg block slides down a plane (inclined at 40° with the horizontal) at a constant speed of 5.0 m/s. At what rate is the gravitational force on the block doing work?

• A) +98 W
• B) +63 W
• C) zero
• D) +75 W
• E) −75 W

---

Definitions:

Lophotrochozoa

A branch of the protostomes that includes the flatworms, nemerteans (proboscis worms), mollusks, annelids, and the lophophorate phyla.

Ecdysozoa

A branch of the protostomes that includes animals that molt, such as the rotifers, nematodes, and arthropods.

Protostomes

A group in the animal kingdom characterized by the mouth developing before the anus during embryonic development.

Coelom

A fluid-filled body cavity found in most multicellular animals that is lined by tissue derived from mesoderm.