A 10-Kg Block Is Pushed Against a Vertical Wall by a Horizontal

question 1

Multiple Choice

A 10-kg block is pushed against a vertical wall by a horizontal force of 100 N as shown in the figure. The coefficient of static friction, $\mu$ _s, between the block and the wall is 0.60; and the coefficient of kinetic friction, $\mu$ _k, is 0.40. Which one of the following statements is true, if the block is initially at rest?

• A)The total force exerted on the block by the wall is directed horizontally.
• B)The block slides down the wall with an acceleration of magnitude 3.8 m/s².
• C)The block will slide down the wall because the force of static friction can be no larger than 60 N.
• D)The block will remain at rest because the coefficient of static friction is greater than the coefficient of kinetic friction.
• E)The block will slide down the wall because the coefficient of kinetic friction is less than the coefficient of static friction.

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Definitions:

Phenoxide Ion

The phenoxide ion is a negatively charged ion (an anion) formed when phenol loses a hydrogen ion (H+), characterized by a phenyl group (C6H5) bound to an oxygen atom carrying a negative charge.

Cyclohexanol

A secondary alcohol with the formula C6H11OH, characterized by a six-member ring structure, and used as a precursor in the production of nylon.

Proton Transfer

The movement of a proton (H+) from one molecule to another, a fundamental process in many chemical and biological reactions.

Sodium Hydroxide

A highly caustic metallic base and alkali salt, commonly known as lye or caustic soda, used in various industrial processes.