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PHY 101 PHY 101 Past Questions Objective Question
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Question

An electric fan is turned off, and its angular velocity decreases uniformly from 500 rev/min to 200 rev/min in 4.00 s. Find the angular acceleration in rev/s² and the number of revolutions made by the motor.
Options
A -1.25 rev/s², 23.3 rev
B -1.52 rev/s², 32.3 rev
C -0.83 rev/s², 23.3 rev
Correct Answer
D -1.25 rev/s², 32.3 rev
Correct Answer

Option C is the correct answer.

Detailed Explanation

500 rev/min = 8.33 rev/s, 200 rev/min = 3.33 rev/s. α = (3.33−8.33)/4 = −1.25 rev/s². Revolutions θ = average ω × t = (8.33+3.33)/2 × 4 = 23.3 rev.

Hint

Convert to rev/s first.

Question Info

Course: PHY 101
Topic: PHY 101 Past Questions
Type: Objective
Difficulty: Not specified
Question 169 of 1250
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