A particle with charge 2.8 C moves through a uniform magneticfield. At one insta

Question

A particle with charge 2.8 C moves through a uniform magneticfield. At one instant the velocity of the particle is (1.4 i +1.2 j + 0.48 k) m/s and the magnetic force on the particle is(11.9 i - 14.1 j + 1.57 k) N. The x andy components of the magnetic field are equal. What are(a) the x-component, (b)the y-component, and (c) thez-component of the magnetic field? I have worked this out twice and the answers are not right...can someone please help? Detailed explanation please. A particle with charge 2.8 C moves through a uniform magneticfield. At one instant the velocity of the particle is (1.4 i +1.2 j + 0.48 k) m/s and the magnetic force on the particle is(11.9 i - 14.1 j + 1.57 k) N. The x andy components of the magnetic field are equal. What are(a) the x-component, (b)the y-component, and (c) thez-component of the magnetic field? I have worked this out twice and the answers are not right...can someone please help? Detailed explanation please.

Explanation / Answer

I will use     x y and z   for the components of the mag field. Using the crossproduct    F = q v (cross) B   wecan write all three components of the force: . x component of force:    11.9 = 2.8 * (1.2 * z - 0.48 * y) . y component of force:     -14.1 = 2.8 * (0.48 * x - 1.4 * z) . z component of force:     1.57 = 2.8 * (1.4 * y - 1.2 * x ) . simplify these and you get... .           17.708 =  5 z -  2 y .         -125.893   = 12 x   - 35 z .           2.8036 = 7 y - 6 x . You are told that   x = y       but you shouldnt need that...you have three equations and three unknowns. Hopefully, it comesout that x = y, because if it doesnt, you have anoverconstrained problem... i.e. three equations and only twounknowns. .    Let's see... .      multiply top equation by7              123.96 = 35 z - 14y .      add to secondequation             123.96 - 125.893 = 35 z - 14y + 12 x - 35 z . or          - 1.935 = 12 x - 14 y . divide by-2              0.9673 = 7y -6x         and thethird equation     2.8036 = 7 y - 6 x . So there's your problem: the problem itself has badnumbers. In other words, what you are given, for the force and thevelocity, are impossible. Some professors assign problems like thiswithout checking the numbers... and they let the students figureout the hard way that the numbers don't work. . Bring this to your prof. It's basic algebra. He should be ableto understand it. . Good luck.

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.