Q- Four equal charges of + 3.0 x 10^{-7} C are placed on the corners of one face of a cube of edge length 10.0 cm. A charge of -3.0 x 10^{-7} C is placed at the center of the cube. What are the magnitude and the direction of the force on the charge at the center of the cube?

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(On request: Fiaza Ali)

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Q- Three particles, each with a mass of 0.25 kg, are located at ( - 4.0 m, 0), (2.0 m, 0), and (0, 3.0 m) and are acted on by forces F_{1} = 3 N along negative y-direction, F_{2} = 5 N along positive y-direction and F_{3} = 4 N along x direction respectively. Find position of center of mass of the system a…

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