A Block of Wood Is Pulled by a Horizontal String

question 14

Multiple Choice

A block of wood is pulled by a horizontal string across a rough surface at a constant velocity with a force of 20 N.The coefficient of kinetic friction between the surfaces is 0.3.The force of friction is

• A)impossible to determine without knowing the mass of the block.
• B)impossible to determine without knowing the speed of the block.
• C)0.3 N
• D)6 N
• E)20 N

---

Definitions:

Principle

A fundamental truth, law, doctrine, or motivating force, upon which others are based or derived.

Relative Motion

The movement of an object in relation to another object, considering both of their movements in a specific frame of reference.

Shape Constancy

The sensory experience in which an object's observed shape stays the same, even when the perspective or distance from which it is seen changes.

Size Constancy

A perceptual phenomenon in which the perceived size of an object remains constant despite changes in the distance from which it is observed.