In the Figure, a 900-Kg Crate Is on a Rough

question 48

Multiple Choice

In the figure, a 900-kg crate is on a rough surface inclined at 30°. A constant external force P = 7200 N is applied horizontally to the crate. While this force pushes the crate a distance of 3.0 m up the incline, its velocity changes from 1.2 m/s to 2.3 m/s. How much work does friction do during this process?

• A) -3700 J
• B) -7200 J
• C) +3700 J
• D) +7200 J
• E) zero

---

Definitions:

Small Discrepancy

a minor difference or deviation from what is expected, generally not sufficient to cause concern.

Auto-motive Theory

The theory suggesting that motivations can be automatically triggered by environmental cues without conscious intention.

Goal-related Stimuli

External cues or information that can influence motivation and action toward achieving a goal.

Higgins's Self-discrepancy Theory

A theory positing that individuals experience emotional discomfort or psychological distress due to discrepancies between their actual self, ideal self (aspirations), and ought self (sense of duty or obligation).