Question Detail

PHY 102 Test Compilation PHY 102 20 Objective Question
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Question

A -2.3x10-6 C charge exerts a repulsive force of magnitude 0.35 N on an unknown charge 0.20 m away. What are the magnitude and polarity of the unknown charge?
Options
A 6.8 x 10-7 C (negative)
Correct Answer
B 6.08 x 107 C (positive)
C 1.2 x 10-6 (negative)
D 1.2 x 10-6 C (positive)
Correct Answer

Option A is the correct answer.

Detailed Explanation

F = k q1 q2 / r2 => q2 = F r2/(k q1) = (0.35)(0.20)2 / [(9x109)(2.3x10-6)] = (0.35)(0.04)/(20700) = 0.014/20700 = 6.76x10-7 C. Since the force is REPULSIVE and the known charge is negative, the unknown charge must also be negative.

Hint

F = k q1 q2 / r2 => q2 = F r2/(k q1) = (0.35)(0.20)2 / [(9x109)(2.3x10-6)] = (0.35)(0.04)/(20700) = 0.014/20700 = 6.76x10-7 C.

Question Info

Course: PHY 102
Topic: Test Compilation PHY 102 20
Type: Objective
Difficulty: Not specified
Question 1241 of 1819
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